US20110307937A1 - Security system for generating keys from access rules in a decentralized manner and methods therefor - Google Patents

Security system for generating keys from access rules in a decentralized manner and methods therefor Download PDF

Info

Publication number
US20110307937A1
US20110307937A1 US13/213,172 US201113213172A US2011307937A1 US 20110307937 A1 US20110307937 A1 US 20110307937A1 US 201113213172 A US201113213172 A US 201113213172A US 2011307937 A1 US2011307937 A1 US 2011307937A1
Authority
US
United States
Prior art keywords
access
key
user
file
secured
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US13/213,172
Inventor
Hal S. Hildebrand
Denis Jacques Paul Garcia
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Intellectual Ventures I LLC
Original Assignee
Guardian Data Storage LLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US10/075,194 external-priority patent/US8065713B1/en
Application filed by Guardian Data Storage LLC filed Critical Guardian Data Storage LLC
Priority to US13/213,172 priority Critical patent/US20110307937A1/en
Publication of US20110307937A1 publication Critical patent/US20110307937A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F21/00Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
    • G06F21/60Protecting data
    • G06F21/62Protecting access to data via a platform, e.g. using keys or access control rules
    • G06F21/6218Protecting access to data via a platform, e.g. using keys or access control rules to a system of files or objects, e.g. local or distributed file system or database
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
    • H04L9/08Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
    • H04L9/0816Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
    • H04L9/0819Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s)
    • H04L9/0825Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s) using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
    • H04L9/32Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
    • H04L9/3226Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials using a predetermined code, e.g. password, passphrase or PIN

Definitions

  • the present invention relates to security systems for data and, more particularly, to security systems that protect data in an inter/intra enterprise environment.
  • the Internet is the fastest growing telecommunications medium in history. This growth and the easy access it affords have significantly enhanced the opportunity to use advanced information technology for both the public and private sectors. It provides unprecedented opportunities for interaction and data sharing among businesses and individuals. However, the advantages provided by the Internet come with a significantly greater element of risk to the confidentiality and integrity of information.
  • the Internet is an open, public and international network of interconnected computers and electronic devices. Without proper security means, an unauthorized person or machine may intercept any information traveling across the Internet and even get access to proprietary information stored in computers that interconnect to the Internet, but are otherwise generally inaccessible by the public.
  • Cryptography allows people to carry over the confidence found in the physical world to the electronic world, thus allowing people to do business electronically without worries of deceit and deception. Every day hundreds of thousands of people interact electronically, whether it is through e-mail, e-commerce (business conducted over the Internet), ATM machines, or cellular phones. The perpetual increase of information transmitted electronically has lead to an increased reliance on cryptography.
  • One of the ongoing efforts in protecting the proprietary information traveling across the Internet is to use one or more cryptographic techniques to secure a private communication session between two communicating computers on the Internet.
  • the cryptographic techniques provide a way to transmit information across an unsecure communication channel without disclosing the contents of the information to anyone eavesdropping on the communication channel.
  • Using an encryption process is a cryptographic technique whereby one party can protect the contents of the data in transit from access by an unauthorized third party, yet the intended party can read the data using a corresponding decryption process.
  • a firewall is another security measure that protects the resources of a private network from users of other networks.
  • many unauthorized accesses to proprietary information occur from the inside, as opposed to from the outside.
  • An example of someone gaining unauthorized access from the inside is when restricted or proprietary information is accessed by someone within an organization who is not supposed to do so.
  • Due to the open nature of the Internet contractual information, customer data, executive communications, product specifications, and a host of other confidential and proprietary intellectual property remain available and vulnerable to improper access and usage by unauthorized users within or outside a supposedly protected perimeter.
  • the invention relates to improved approaches for decentralized key generation.
  • the keys that can be generated include both public keys and private keys.
  • the public keys are arbitrary strings that embed or encode access restrictions.
  • the access restrictions are used to enforce access control policies.
  • the public keys are used to encrypt some or all portions of files.
  • the private keys can be generated to decrypt the portions of the files that have been encrypted with the public keys.
  • the invention can be implemented in numerous ways, including as a method, system, device, and computer readable medium. Several embodiments of the invention are discussed below.
  • one embodiment of the invention includes at least the acts of: obtaining access rules to be imposed; producing a rules string in accordance with the access rules; generating a public key based on the rules string; and encrypting at least a portion of the file using the public key.
  • one embodiment of the invention includes at least the acts of: identifying access rules to be imposed; producing a rules string in accordance with the access rules; obtaining a key block of the file to be encrypted, the file including at least the key block and a data block; generating a public key for the key block based on the rules string; and encrypting the key block portion of the file using the public key.
  • one embodiment of the invention includes at least the acts of: obtaining a key string associated with the secured file to be decrypted; identifying access rules associated with the key string; evaluating the access rules to determine whether a user requesting access to the secured file is permitted access to the secured file; denying access to the secured file when said evaluating determines that the access rules do not permit the user to access the secured file; generating a private key based on the access rules and a master key when said evaluating determines that the access rules permit the user to access the secured file; and decrypting, following said generating, at least a portion of the secured file for access thereto by the user through use of the private key.
  • one embodiment of the invention includes at least the acts of: obtaining a key string associated with the secured file to be decrypted; identifying access rules associated with the key string; obtaining an encrypted key block of the secured file; evaluating the access rules to determine whether a user requesting access to the secured file is permitted access to the secured file; denying access to the secured file when said evaluating determines that the access rules do not permit the user to access the secured file; generating a private key based on the access rules and a master key when said evaluating determines that the access rules permit the user to access the secured file; decrypting, following said generating, the encrypted key block to obtain a file key; and thereafter decrypting at least a portion of the secured file for access thereto by the user through use of the file key.
  • one embodiment of the invention includes at least: computer program code for obtaining access rules to be imposed; computer program code for producing a rules string in accordance with the access rules; computer program code for generating a public key based on the rules string; and computer program code for encrypting at least a portion of the file using the public key.
  • one embodiment of the invention includes at least: computer program code for obtaining a key string associated with the secured file to be decrypted; computer program code for identifying access rules associated with the key string; computer program code for evaluating the access rules to determine whether a user requesting access to the secured file is permitted access to the secured file; computer program code for denying access to the secured file when said evaluating determines that the access rules do not permit the user to access the secured file; computer program code for generating a private key based on the access rules and a master key when said evaluating determines that the access rules permit the user to access the secured file; and computer program code for decrypting at least a portion of the secured file for access thereto by the user through use of the private key.
  • FIG. 1A shows a basic system configuration in which the invention may be practiced in accordance with an embodiment thereof.
  • FIG. 1B shows another system configuration in which the invention may be practiced in accordance with an embodiment thereof.
  • FIG. 1C shows still another system configuration in which the invention may be practiced in accordance with an embodiment thereof.
  • FIG. 1D shows internal construction blocks of a computing device in which the invention may be implemented and executed.
  • FIG. 2A is a block diagram of securing a created document according to one embodiment of the invention.
  • FIG. 2B illustrates an exemplary structure of a secured document including a header and an encrypted portion.
  • FIG. 3A illustrates a representative data structure of a secured file including a header and an encrypted data portion according to one embodiment of the invention.
  • FIG. 3B is a functional block diagram of a server device in accordance with one embodiment of the invention.
  • FIG. 3C is a functional block diagram of a local server device according to one embodiment of the invention.
  • FIG. 3D is a functional block diagram of a client machine according to one embodiment of the invention.
  • FIG. 4 is a block diagram of a file security system according to one embodiment of the invention.
  • FIG. 5 is a block diagram of a distributed file security system according to one embodiment of the invention.
  • FIG. 6 is a flow diagram of access rules based encryption processing according to one embodiment of the invention.
  • FIG. 7 is a flow diagram of access rules based decryption processing according to one embodiment of the invention.
  • FIG. 8 is a flow diagram of access rules based encryption processing according to another embodiment of the invention.
  • FIG. 9 is a flow diagram of access rules based decryption according to another embodiment of the invention.
  • FIG. 10 illustrates flow diagrams of an authorization process according to one embodiment of the invention.
  • FIG. 11 shows a flowchart of a user authentication process that may be implemented in a server, such as an access server, a central server or a local server.
  • a server such as an access server, a central server or a local server.
  • the invention relates to improved approaches for decentralized key generation.
  • the keys that can be generated include both public keys and private keys.
  • the public keys are arbitrary strings that embed or encode access restrictions.
  • the access restrictions are used to enforce access control policies.
  • the public keys are used to encrypt some or all portions of files.
  • the private keys can be generated to decrypt the portions of the files that have been encrypted with the public keys.
  • a user may mean a human user, a software agent, a group of users, a member of the group, a device and/or application. Besides a human user who needs to access a secured document, a software application or agent sometimes needs to access secured files in order to proceed. Accordingly, unless specifically stated, the “user” as used herein does not necessarily pertain to a human being.
  • Secured files are files that require one or more keys, passwords, access privileges, etc. to gain access to their content.
  • the security is provided through encryption and access rules.
  • the files can pertain to documents, multimedia files, data, executable code, images and text.
  • a secured file can only be accessed by authenticated users with appropriate access rights or privileges.
  • Each secured file is provided with a header portion and a data portion, where the header portion contains, or points to, security information. The security information is used to determine whether access to associated data portions of secured files is permitted.
  • references herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention.
  • the appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Further, the order of blocks in process flowcharts or diagrams representing one or more embodiments of the invention do not inherently indicate any particular order nor imply any limitations in the invention.
  • FIGS. 1A-11 Embodiments of the present invention are discussed herein with reference to FIGS. 1A-11 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments.
  • FIG. 1A shows a basic system configuration in which the present invention may be practiced in accordance with one embodiment thereof.
  • Documents or files may be created using an authoring tool executed on a client computer 100 , which may be a desktop computing device, a laptop computer, or a mobile computing device.
  • client computer 100 may be a desktop computing device, a laptop computer, or a mobile computing device.
  • Exemplary authoring tools may include application programs such as Microsoft Office (e.g., Microsoft Word, Microsoft PowerPoint, and Microsoft Excel), Adobe FrameMaker and Adobe Photoshop.
  • the client computer 100 is loaded with a client module that is capable of communicating with a server 104 or 106 over a data network (e.g., the Internet or a local area network).
  • a data network e.g., the Internet or a local area network
  • the client computer 100 is coupled to the server 104 through a private link.
  • a document or file created by an authoring tool can be secured by the client module.
  • the client module when executed, is configured to ensure that a secured document is secured at all times in a store (e.g., a hard disk or other data repository).
  • the secured documents can only be accessed by users with proper access privileges.
  • an access privilege or access privileges for a user may include, but not be limited to, privileges pertaining to viewing, copying, printing, editing, transferring, uploading/downloading, and location.
  • a created document is caused to go through an encryption process that is preferably transparent to a user.
  • the created document is encrypted or decrypted under the authoring application so that the user is not aware of the process.
  • a key (referred to herein as a user key) can be used to retrieve a file key to decrypt an encrypted document.
  • the user key is associated with an access privilege for the user or a group of users. For a given secured document, only a user with a proper access privilege can access the secured document.
  • a secured document may be uploaded via the network 110 from the computer 100 to a computing or storage device 102 that may serve as a central repository.
  • the network 110 can provide a private link between the computer 100 and the computing or storage device 102 .
  • Such link may be provided by an internal network in an enterprise or a secured communication protocol (e.g., VPN and HTTPS) over a public network (e.g., the Internet).
  • a secured communication protocol e.g., VPN and HTTPS
  • public network e.g., the Internet
  • such link may simply be provided by a TCP/IP link.
  • secured documents on the computer 100 may be remotely accessed.
  • the computer 100 and the computing or storage device 102 are inseparable, in which case the computing or storage device 102 may be a local store to retain secured documents or receive secured network resources (e.g., dynamic Web contents, results of a database query, or a live multimedia feed).
  • secured documents or secured resources e.g., dynamic Web contents, results of a database query, or a live multimedia feed.
  • a user can access the secured documents or resources from the computer 100 or the computing or storage device 102 using an application (e.g., Internet Explorer, Microsoft Word or Acrobat Reader).
  • an application e.g., Internet Explorer, Microsoft Word or Acrobat Reader
  • the server 104 also referred to as a local server, is a computing device coupled between a network 108 and the network 110 . According to one embodiment, the server 104 executes a local version of a server module. The local version is a localized server module configured to service a group of designated users or client computers, or a location.
  • Another server 106 also referred to as a central server, is a computing device coupled to the network 108 .
  • the server 106 executes the server module and provides centralized access control management for an entire organization or business. Accordingly, respective local modules in local servers, in coordination with the central server, form a distributed mechanism to provide distributed access control management. Such distributed access control management ensures the dependability, reliability and scalability of centralized access control management undertaken by the central server for an entire enterprise or a business location.
  • FIG. 1B shows another system configuration in which the invention may be practiced in accordance with an embodiment thereof.
  • the configuration employs a central server and local servers.
  • the configuration may correspond to a large enterprise having multiple geographic locations or offices.
  • a central server 106 maintains a database managing the access privileges and the access rules in the entire enterprise.
  • One of the features in this configuration is the underlying capability to provide fault tolerance and efficient AC (Access Control) management for a large group of users.
  • a number of local servers 104 e.g., 104 -A, 104 -B, . . . and 104 -N
  • a number of local servers 104 e.g., 104 -A, 104 -B, . . . and 104 -N
  • Each of local servers 104 executes a local module derived or duplicated from the server module being executed at the central server 106 to manage those users who are local to respective local servers 104 .
  • the central server 106 can centralize the AC management in addition to managing the users if necessary.
  • a local module can be a customized version of the server module that runs efficiently for only a few locations or a group of users.
  • a local server 104 -A is only responsible for the users or computers 102 -A in location A
  • a local server 104 -B is only responsible for the users or computers 102 -B in location B.
  • the central server 106 has to be taken down for maintenance or is not operative at the time a user needs to access secured documents, the access control will not be disrupted.
  • the detailed operation of the local servers 104 in cooperation with the central server 106 will be further described below.
  • a local module is a replicated version of the server module and exchanges any updates with the server module when connected (e.g., periodically or at request).
  • part or all of the server module can be duplicated in a local server to ensure that communications with users or their client machines are efficient and fault tolerance.
  • the access control will not be disruptive.
  • any of the local servers 104 can step up and take the place of the central server.
  • FIG. 1C shows still another system configuration in which the invention may be practiced in accordance with an embodiment thereof.
  • This configuration is suitable for a small group of users.
  • no local servers are employed.
  • a server computer 112 is loaded with the server module and each of the users or terminal computers 116 (only one is shown therein) is loaded with a client module.
  • the users or the terminal computers 16 couple to the server computer 112 through a local area network.
  • the server computer 112 performs the AC management for each of the users or the terminal computers 116 .
  • FIG. 1D shows internal construction blocks of a computing device 118 in which one embodiment of the present invention may be implemented and executed.
  • the computing device 118 may correspond to a client device (e.g., computer 100 , computing or storage device 102 in FIG. 1A ) or a server device (e.g., server 104 , 106 in FIG. 1A ).
  • the computing device 118 includes a central processing unit (CPU) 122 interfaced to a data bus 120 .
  • the CPU 122 executes instructions to process data and perhaps manage all devices and interfaces coupled to data bus 120 for synchronized operations.
  • the instructions being executed can, for example, pertain to drivers, operating system, utilities or applications.
  • Device interface 124 may be coupled to an external device, such as the computing device 102 of FIG. 1A ; hence, the secured documents therefrom can be received into memory 132 or storage 136 through data bus 120 . Also interfaced to data bus 120 is a display interface 126 , a network interface 128 , a printer interface 130 and a floppy disk drive interface 138 . Generally, a client module, a local module or a server module of an executable version of one embodiment of the present invention can be stored to storage 136 through floppy disk drive interface 138 , network interface 128 , device interface 124 or other interfaces coupled to data bus 120 . Execution of such module by the CPU 122 can cause the computing device 118 to perform as desired in the present invention. In one embodiment, the device interface 124 provides an interface for communicating with a capturing device 125 (e.g., a fingerprint sensor, a smart card reader or a voice recorder) to facilitate the authentication of a user of the computing device 118 .
  • Main memory 132 such as random access memory (RAM) is also interfaced to data bus 120 to provide the CPU 122 with instructions and access to memory storage 136 for data and other instructions.
  • RAM random access memory
  • the CPU 122 is caused to manipulate the data to achieve results contemplated by the program instructions.
  • Read-only memory (ROM) 134 is provided for storing executable instructions, such as a basic input/output operation system (BIOS) for operation of keyboard 140 , display 126 and pointing device 142 which may be present.
  • BIOS basic input/output operation system
  • the computing device 118 is capable of storing secured items (e.g., secured files) in the main memory 132 or the storage 136 .
  • the main memory 132 provides non-persistent (i.e., volatile) storage for the secured items and the storage 136 provides persistent (i.e., non-volatile) storage for the secured items.
  • the computing or storage device 102 or more particularly, the main memory 132 and/or the storage 136 , can act as a storage device for the secured items.
  • the created document 200 is a created file.
  • an application or authoring tool e.g., Microsoft Word
  • a command such as “Save,” “Save As” or “Close”, or automatic saving invoked by an operating system, the application itself or an approved application, the created document 200 is caused to undergo a securing process 201 .
  • the securing process 201 starts with an encryption process 202 , namely the document 200 that has been created or is being written into a store is encrypted by a cipher (e.g., an encryption process) with a file key (i.e., a cipher key), in other words, the encrypted data portion 212 could not be opened without the file key.
  • a cipher e.g., an encryption process
  • a file key i.e., a cipher key
  • the file key or keys may be the same or different keys for encryption and decryption and are included as part of security information contained in or pointed to by a header 206 .
  • the file key or keys once obtained, can be used to decrypt the encrypted data portion 212 to reveal the contents therein.
  • a set of access rules 204 for the document 200 is received or created and associated with the header 206 .
  • the access rules 204 determine or regulate who and/or how the document 200 , once secured, can be accessed. In some cases, the access rules 204 also determine or regulate when or where the document 200 can be accessed.
  • security clearance information 207 can be added to the header 206 if the secured file 208 is classified.
  • the security clearance information 207 is used to determine a level of access privilege or security level of a user that is attempting to access the contents in the secured file 208 .
  • a secured file may be classified as “Top secret”, “Secret”, “Confidential”, and “Unclassified”.
  • the security clearance information 207 includes another layer of encryption of the file key with another key referred to herein as a clearance key. An authorized user must have a clearance key of proper security level in addition to an authenticated user key and proper access privilege to retrieve the file key.
  • a user key or a group key is a cipher key associated with an authenticated user and may be used to access a secured file or secure a file, or create a secured file. Additional detail on obtaining such a user key upon a user being authenticated is provided in U.S. patent application Ser. No. 10/074,194, which is hereby incorporated herein by reference.
  • the security clearance information 207 includes a set of special access rules to guard the file key.
  • the retrieval of the file key requires that the user pass an access rule measurement. Since access privilege of a user may be controlled via one or more system parameters (e.g., rules or policies), the access rule measurement can determine if the user has sufficient access privilege to retrieve the file key in conjunction with the corresponding user key.
  • a user may be assigned a hierarchical security clearance level based on, perhaps, a level of trust assigned to the user.
  • a level of trust implies that one user may be more trusted than another and hence the more trusted user may access more classified files.
  • a level of trust may be based on job responsibility of the user or a role of the user in a project or an organization background checks, psychological profiles, length of service, etc.
  • a level of trust assigned to the user augments additional aspect to the access privilege of the user such that the user must have proper security clearance to access a classified secured file even if the user is permitted by the access rules to access the file.
  • a header is a file structure, preferably small in size, and includes, or perhaps links to, security information about a resultant secured document.
  • the security information can be entirely included in a header or pointed to by a pointer that is included in the header.
  • the security information further includes the file key and/or one or more clearance keys, in some cases, an off-line access permit (e.g., in the access rules) should such access be requested by an authorized user.
  • the security information is then encrypted by a cipher (i.e., an encryption/decryption scheme) with a user key associated with an authorized user to produce encrypted security information 210 .
  • the encrypted header 206 if no other information is added thereto, is attached to or integrated with the encrypted data portion 212 to generate the resultant secured file 208 .
  • the header is placed at the beginning of the encrypted document (data portion) to facilitate an early detection of the secured nature of a secured file.
  • One of the advantages of such placement is to enable an access application (i.e., an authoring or viewing tool) to immediately activate a document securing module (to be described where it deems appropriate) to decrypt the header if permitted. Nevertheless, there is no restriction as to where the encrypted header 206 is integrated with the encrypted data portion 212 .
  • a cipher may be implemented based on one of many available encryption/decryption schemes. Encryption and decryption generally require the use of some secret information, referred to as a key. For some encryption mechanisms, the same key is used for both encryption and decryption; for other mechanisms, the keys used for encryption and decryption are different.
  • data can be encrypted with a key according to a predetermined cipher (i.e., encryption/decryption) scheme. Examples of such schemes may include, but not be limited to, Data Encryption Standard algorithm (DES), Blowfish block cipher and Twofish cipher. Therefore, the operations of the present invention are not limited to a choice of those commonly-used encryption/decryption schemes. Any cipher scheme that is effective and reliable may be used. Hence, the details of a particular scheme are not further discussed herein so as to avoid obscuring aspects of the present invention.
  • DES Data Encryption Standard algorithm
  • the secured document 208 includes two parts, the encrypted data portion 212 (i.e., encrypted version of the document itself) and the header 210 that may point to or include encrypted security information for the secured document 208 .
  • the encrypted data portion 212 i.e., encrypted version of the document itself
  • the header 210 may point to or include encrypted security information for the secured document 208 .
  • To access the contents in the encrypted data portion 212 one needs to obtain the file key to decrypt the encrypted data portion 212 .
  • To obtain the file key one needs to be authenticated to get a user or group key and pass an access test in which at least the access rules in the security information are measured against the user's access privilege (i.e., access rights). If the secured file is classified, it further requires a security level clearance on the user. In general, the security clearance level of the user must be high enough before the file key can be retrieved.
  • FIG. 2B illustrates an exemplary structure of a secured document 220 including a header 222 and an encrypted portion 224 .
  • the header 222 includes a security information block 226 having encrypted security information that essentially controls the access to the encrypted document 224 .
  • the header 222 includes a flag 227 (e.g., a predetermined set of data) to indicate that the document 220 is secured.
  • the security information block 226 includes one or more user IDs 228 , access rules 229 , at least one file key 280 and other information 231 .
  • the user IDs 228 maintain a list of authorized users who may be measured against the access rules 229 before the file key 230 can be retrieved.
  • the access rules 229 determine at least who and how the encrypted document 224 can be accessed.
  • the other information 231 may be used to include other information facilitating a secure access to the encrypted document 224 , the example may include version numbers or author identifier.
  • a document is encrypted with a cipher (e.g., a symmetric or asymmetric encryption scheme).
  • Encryption is the transformation of data into a form that is impossible to read without appropriate knowledge (e.g., a key). Its purpose is to ensure privacy by keeping information hidden from anyone to whom it is not intended, even those who have access to other encrypted data.
  • Decryption is the reverse of encryption. Encryption and decryption generally require the use of some secret information, referred to as a key. For some encryption mechanisms, the same key is used for both encryption and decryption; for other mechanisms, the keys used for encryption and decryption are different.
  • the key or keys may be the same or different keys for encryption and decryption and are preferably included in the security information (e.g., security information block 226 ) contained in or pointed to by the header (header 222 ) and, once obtained, can be used to decrypt the encrypted document.
  • security information e.g., security information block 226
  • the key itself is guarded by the access privileges and rules. If a user requesting the document has the adequate access privileges given the requirement of the access rules, the key will be retrieved so as to permit the decryption of the encrypted document.
  • the header itself can be encrypted with a cipher.
  • the cipher for the header may or may not be identical to the one used for the document.
  • the key (referred to as a user key) to decrypt the encrypted header can, for example, be stored in a local store of a terminal device (e.g., client computer) and activated only when the user associated with it is authenticated. As a result, only an authorized user can access the secured document.
  • the two encrypted portions can be encrypted again and only decrypted by a user key.
  • the encrypted portions can be error checked by error checking portion 225 , such as using a cyclical redundancy check to ensure that no errors have been incurred to the encrypted portion(s) or the secured document 220 .
  • each of the users in a security system is assigned a user key or user keys (e.g., a user public key and a private key).
  • the user key is also referred to as a group key if a user is a member of group (e.g., Engineering) that has uniform access privilege.
  • the user public key is used to encrypt some or all of the security information in the header and the user private key is used to get into the security information or header for the purpose of retrieving the file or document key so as to decrypt the encrypted data portion or the encrypted document.
  • a user key herein indicates either or both of the user public key and the private key or a security key that is needed in the system to retrieve the file key to decrypt the encrypted data portion.
  • a user may have different access privileges, some may access all secured files while others may access some of the secured files with restricted actions (i.e., printing, reading or editing, but not forwarding). Whether a user can ultimately achieve the access to the encrypted data portion in a secured file is controlled by the access rules or additional key(s) in the security information of the header. Limited by a user's access privilege, a user key associated with the user may facilitate access to all secured files.
  • FIG. 3A illustrates a representative data structure of a secured file 300 including a header 302 and an encrypted data portion 304 according to one embodiment of the invention.
  • the secured file 300 is secured by access rules and use of encryption. A user must possess a user key, a protection key, a file key and sometimes a clearance key in order to access the secured file 300 .
  • the header 302 may or may not include a flag or signature 306 . In one case, the signature 306 is used to facilitate the detection of the security nature of a secured file among other files.
  • the header 302 includes a file key block 308 , a key block 310 and a rule block 312 .
  • the file key block 308 includes a file key 309 that is encrypted by a cipher with a protection key 320 (i.e., a doc-key key sometimes) and further with a clearance key 322 associated with a user that attempts to access the secured file 300 .
  • the file key 309 is encrypted with the clearance key 322 and then the protection key 320 .
  • the protection key 320 is encrypted and stored in the key block 310 .
  • the key block 310 has an encrypted version of the protection key 320 and can be only accessible by designated user(s) or group(s). There may be more than one key blocks 310 in a header, wherein three key blocks are shown in FIG. 3A .
  • a designated user must have proper access privilege to pass an access rule test with the embedded access rules in the rule block 312 .
  • All access rules are encrypted with a user key (e.g., a public user key) and stored in the rule block 312 .
  • a user attempting to access the secured file uses must have a proper user key (e.g., a private user key) to decrypt the access rules in the rule block 312 .
  • the access rules are then applied to measure the access privileges of the user. If the user is permitted to access the secured file in view of the access rules, the protection key 320 in the key block 310 is retrieved to retrieve the file key 309 so as to access the encrypted data portion 304 . However, when it is detected that the secured file is classified, which means that the file key can not be retrieved with only the protection key, the user must posses a clearance key. Only the user that has the clearance key and the retrieved protection key 320 is able to retrieve the file key 309 and proceed with the decryption of the encrypted data portion 304 .
  • the encrypted data portion 304 is produced by encrypting a file that is non-secured.
  • a non-secured document can be created by an authoring tool (e.g., Microsoft Word).
  • the non-secured document is encrypted by a cipher with the file key.
  • the encryption information and the file key are then stored in the security information, namely, the file key block 308 of the header 302 .
  • the non-secured document is encrypted using the following aspects, a strong encryption using a CBC mode, a fast random access to the encrypted data, and an integrity check.
  • the data is encrypted in blocks.
  • the size of each block may be a predetermined number or specific to the document.
  • the predetermined number may be a multiple of an actual encryption block size used in an encryption scheme.
  • One of the examples is a block cipher (i.e., a type of symmetric-key encryption algorithm that transforms a fixed-length block of plaintext (unencrypted text) data into a block of ciphertext (encrypted text) data of the same length.
  • This transformation takes place under the action of a cipher key (i.e., a file key).
  • Decryption is performed by applying the reverse transformation to the ciphertext block using another cipher key or the same cipher key used for encryption.
  • the fixed length is called the block size, such as 64 bits or 128.
  • Each block is encrypted using a CBC mode.
  • a unique initiation vector (IV) is generated for each block.
  • encryption information and the file key are then stored in the security information.
  • One aspect of the present invention is that the integration of a header and the encrypted data portion will not alter the original meaning of the data that is otherwise not secured.
  • a designated application may still be activated when a secured file is selected or “clicked”. For example, a document “xyz.doc”, when selected, will activate an authoring tool, e.g., Microsoft Word, commonly seen in a client machine.
  • the resultant secured file is made to appear the same, “xyz.doc” that still can activate the same authorizing tool, except now the secured file must go through a process to verify that a user is authenticated, the user has the proper access privilege and (if imposed) sufficient security clearance.
  • the file key can be updated without having to modify the key-blocks.
  • the file key 309 in the file key block 30 can be updated without having to modify the key-blocks 310 .
  • One of the features in the structure shown in FIG. 3A is that the underlying mechanism facilitates the updating and management of the file key.
  • the access rules were encrypted with a user's public key.
  • the access rules can be encrypted in other ways.
  • the access rules may be also encrypted with a file encryption key (i.e., the file key) or the protection key.
  • the protection key is encrypted with a user's public key or together with a clearance key associated with the user if a subject secured file is secured.
  • the protection key can be retrieved first with a user's private key.
  • the protection key can be used to retrieve the access rules that are subsequently used to measure against the access privilege of the user if the protection key was used to encrypt the access rules. If the user is permitted to access the contents in the file, the file key is then retrieved with the protection key (or together with the clearance key). Alternatively, right after the protection key is retrieved, the protection key (or together with the clearance key) is used to retrieve the file key. The file key is then to retrieve the access rules that are subsequently used to measure against the access privilege of the user. In any case, if the user is determined have sufficient access privilege in view of all access policies, if there are any, the retrieved file key can be used to continue the decryption of the encrypted data portion.
  • a secured document may be configured differently than noted above without departing from the principles of the present invention.
  • a secured document may include a header with a plurality of encrypted headers, each can be accessible only by one designated user or a group users.
  • a header in a secured document may include more than one set of security information or pointers thereto, each set being for one designated user or a group of users while a single file key can be used by all.
  • Some or all of the access rules may be viewed or updated by users who can access the secured document.
  • the header can include at least one pointer which points to a remote data structure stored in a storage device.
  • the remote data structure can store some or all of the security information, thereby shortening the size of the header and improving manageability of security information.
  • the storage device is typically a local storage device.
  • the alternative data structure and the remote data structure are typically stored on a common machine (e.g., desktop or portable computer).
  • the data structure stores security information. Additional details on the alternative data structure can be found in U.S. application Ser. No. 10/132,712 (Att. Dkt.: SSL1P005/SS-14), filed Apr. 26, 2002, and entitled “METHOD AND SYSTEM FOR PROVIDING MANAGEABILITY TO SECURITY INFORMATION FOR SECURED ITEMS,” which is hereby incorporated herein by reference.
  • the access rules are present in a descriptive language such as text or a markup language (e.g., HTML, SGML and XML).
  • the markup language is eXtensible Access Control Markup Language (XACML) that is essentially an XML specification for expressing policies for information access.
  • XACML can address fine-grained control of authorized activities, the effect of characteristics of the access requestor, the protocol over which the request is made, authorization based on classes of activities, and content introspection (i.e., authorization based on both the requestor and attribute values within the target where the values of the attributes may not be known to the policy writer).
  • XACML can suggest a policy authorization model to guide implementers of the authorization mechanism.
  • the data portion of a secured item is a document or file encrypted with a cipher (e.g., a symmetric or asymmetric encryption scheme).
  • Encryption is the transformation of data into a form that is impossible to read without appropriate knowledge (e.g., a key). Its purpose is to ensure privacy by keeping information hidden from anyone to whom it is not intended, even those who have access to other encrypted data.
  • Decryption is the reverse of encryption. Encryption and decryption generally require the use of some secret information, referred to as a key. For some encryption mechanisms, the same key is used for both encryption and decryption; for other mechanisms, the keys used for encryption and decryption are different.
  • the key or keys may be the same or different keys for encryption and decryption and are preferably included in the security information contained in, or pointed to by, the header and, once obtained, can be used to decrypt the encrypted document.
  • the key itself is guarded by the access privileges and rules. If a user requesting the document has the proper access privileges that can be granted by the access rules and system policies if there are any, the key will be retrieved to proceed with the decryption of the encrypted document.
  • the header itself can be encrypted with a cipher.
  • the cipher for the header may or may not be identical to the one used for the document.
  • the key (referred to as a user key) to decrypt the encrypted header can, for example, be stored in a local store of a terminal device and activated only when the user associated with it is authenticated. As a result, only an authorized user can access the secured document.
  • the key is associated with a user's login to a local server or a central server. Appropriate access privileges associated with the user can then be validated if the user has been authenticated or previously registered with the server and properly logged in.
  • the two portions i.e., the header (possibly encrypted) and the encrypted document
  • the encrypted portions can be error-checked by an error-checking portion, such as using a cyclical redundancy check to ensure that no errors have been incurred to the encrypted portion(s) of the secured document.
  • the security system according to the invention can, in general, include or make use of one to many user computers and at least one central server.
  • the security system can also include or make use of one or more local servers as desired. In other words, the security systems operate in a distributed fashion.
  • the server device includes a server module 322 that resides in a memory space 323 and is executable by one or more processors 321 .
  • the server device 320 also includes a network interface 324 to facilitate the communication between the server 320 and other devices on a network, and a local storage space 325 .
  • the server module 322 is an executable version of one embodiment of the present invention and delivers, when executed, features/results contemplated in the present invention.
  • the server module 322 comprises an administration interface 326 , an account manager 328 , a system parameter manager 330 , a user monitor 332 , a local server manager 334 , a partner access manager 336 , an access report manager 338 , and a rules manager 339 .
  • the administration interface 326 facilitates a system administrator to register users and grant respective access privileges to the users and is an entry point to the server module from which all sub-modules or the results thereof can be initiated, updated and managed.
  • the system administrator sets up hierarchy access levels for various active folders, storage locations, users or group of users.
  • the privileges may include, but not be limited to: open, read, write, print, copy, download and others Examples of the other privileges are altering access privileges for other users, accessing secured documents from one or more locations, and setting up a set of access rules for a folder different from those previously set up (perhaps by the system administrator).
  • the respective user IDs assigned to the users facilitate the management of all the users.
  • a user or a corresponding user ID is interchangeably used herein to identify a human user, a software agent, or a group of users and/or software agents. Besides a human user who needs to access a secured document, a software application or agent sometimes needs to access the secured document in order to proceed forward. Accordingly, unless specifically stated, the “user” as used herein does not necessarily pertain to a human being. In general, a user that will access a secured document is associated with a user key to allow an encrypted header in a secured document to be unlocked (decrypted). The expiration or regeneration of a user key may be initiated by the system administrator. According to one embodiment, the administration interface 326 is a user graphic interface showing options for various tasks that an authenticated system administrator or operator may need to perform.
  • the account manager is a database or an interface to a database 327 (e.g., an Oracle database) maintaining all the registered users and their respective access privileges, and perhaps corresponding user keys (e.g., private and public keys).
  • a database 327 e.g., an Oracle database
  • user keys e.g., private and public keys.
  • the account manager 328 authenticates a user when the user logs onto the server 320 and also determines if the user can access secured documents from the location the user's current location.
  • This module is configured to manage system parameters within the server module 322 .
  • system parameters include, for example, user access privileges, system rules, and one or more keys.
  • the system parameters manager 330 can be used to add, delete or modify any of the system parameters.
  • the system parameters manager 330 can also interact with local modules and client modules to supply the system parameters to these distributed modules. For example, a user key can be expired (deleted) for security reasons when a user leaves the organization or when its time to replace the user key. As another example, a file key may be rotated on a periodic or on-demand basis.
  • the system parameters can be supplied to local modules and client modules by a “push” of system parameters to the other distributed modules or by a response to a “pull” request for updated system parameters.
  • the system parameters manager 330 may be further configured to act as a key manager managing all keys used in the security system.
  • This module is configured to monitor user's requests and whereabouts.
  • a user is granted to access secured documents from one or more designated locations or networked computers. If a user has a higher access privilege (e.g., to permit access from other than the locations or networked computers), the user monitor 332 may be configured to ensure that the user can have only one access from one of the registered locations or computers at all times.
  • the user monitor 332 may be configured and scheduled to interact with the system parameters manager 330 to “push” an update of system parameters or respond to a “pull” request for an update of system parameters.
  • This module is designed to be responsible for distributing an appropriate local module for a local server servicing a predetermined location or a predetermined group of users.
  • the local server manager 334 replicates some or all of the server module 322 being executed on the server 320 and distributes the replicated copy to all the local servers.
  • a user can access secured documents anywhere within the network premises covered by the local servers without being authenticated at a single central server, namely the server 320 .
  • the local server manager 334 replicates some of the server module 322 being executed on the server 320 and distributes the replicated copy to a corresponding local server, in this embodiment, each of the local servers will have its own customized replication from the server module 322 .
  • a special module to manage non-employees accounts may be consultants to a business that requires the consultants to access certain secured documents.
  • the partners access manager 336 generally works in accordance with other modules in the server but puts additional restrictions on such users being directly managed by the partners access manager 336 .
  • the partners access manager 336 generates a request to the user key manager 330 to expire a key or key pair for a consultant when an engagement with the consultant ends.
  • a module is configured to record or track possible access activities and primarily works with a corresponding sub-module in a client module being executed in a client machine.
  • the access report manager 338 is preferably activated by the system administrator and the contents gathered in the access report manager 338 and is typically only accessible by the system administrator.
  • the rules manager 339 is an enforcement mechanism of various access rules.
  • the rules manager 339 is configured to specify rules based on i) data types (e.g., Microsoft Word), ii) group users or individual, iii) applicable rights, and iv) duration of access rules.
  • a set of rules is a policy (namely, a security policy).
  • a policy can be enabled, disabled, edited, deployed and undone (e.g., one or two levels).
  • Policies managed by the rules manager 339 operate preferably on a global level.
  • the rules (as well as other system parameters) are typically downloaded to the client machine during the login process (after the user is authenticated) and can be updated dynamically.
  • respective policies may be associated with active folders (i.e., those designated places to store secured documents). These polices are also downloaded and updated on the client machine. Simple policies can also be embedded in the document and provide document specific policies.
  • a header is received by a local server from a client and the access rules from the header are retrieved.
  • the key manager 330 can be called upon to decrypt the encrypted security information in the header.
  • the rules manager 339 can then parse the access rules from the security information and evaluate or measure the access rules against the access privileges of the user to determine whether the secured document can be accessed by the user. If the evaluation or measurement succeeds, a file key is retrieved and sent back to the client.
  • server module 322 in FIG. 3B lists some exemplary modules according to one embodiment of the present invention and not every module in the server module 322 has to be implemented in order to practice the present invention.
  • FIG. 3C shows a functional block diagram of a local server device 340 according to one embodiment of the invention.
  • the local server device 340 executes a module, referred herein as a local module 342 which is configured to be a complete or partial replication of the server module 322 of FIG. 3B .
  • the local server device 340 is generally similar to that of a server as illustrated in FIG. 3B . Namely, the local server device 340 includes one or more processors 341 , a memory space 343 , a network interface 344 , and a local storage space 345 . Given the similarity, many parts illustrated in FIG. 3C are not to be described again to avoid obscuring aspects of the present invention.
  • the local module 342 provides the dependability, reliability and scalability of the centralized access control management being undertaken by the central server 320 of FIG. 3B . As such, not all authentication requests need to be handled at one central point without losing control of the access control management. The users are thus not affected if the central server is brought down for maintenance and the connection to the central server is not available. If a number of local servers are used and each has a replication of the server module, the reliability of servicing the users is greatly enhanced. As a result, the local users need only to check with the corresponding local server and none of the users would be affected if other local servers are down for whatever reasons or disconnected from the central server.
  • the configuration of a user's access to secured documents is sometimes referred to as a provisioning process.
  • the dynamic provisioning that has been deserted above is believed to provide the necessary security means needed by a large enterprise having employees in several locations without the loss of the centralized access control management at a central server. Further, the use of multiple local servers to support the central server can provide increased dependability, reliability and sociability.
  • the client machine 360 is a computing device primarily used by a user to access secured documents.
  • the client machine 360 can, for example, be a desktop computer, a mobile device or a laptop computer.
  • the client machine 360 includes a processor 361 , a client module 362 , a memory space 363 , a network interface 365 and a local store 367 .
  • the client module 362 resides in the memory space 363 and, when executed by the processor 361 , delivers features, advantages and benefits contemplated in the present invention.
  • the client machine 360 is capable of communicating over a data network with other computers, such as a server. From the client machine 360 , a user can access secured documents located in a repository (store) 366 that may be in the client machine 360 , another networked device, or other storage means.
  • the client module 362 includes a number of sub-modules including an access report module 364 , a user verifying module 370 , a key manager 368 , a document securing module 371 and an off-line access manager 374 .
  • This module is a software agent configured to record access activity and associated with an authenticated user. It reports to an access report module in the central server so that a record may be established as to what secured document has been accessed by which user during what time.
  • the access report module 364 can be activated to capture access activities of the user when the client machine is not networked. The access activities will be later synchronized with the counterpart in the server to facilitate the access control management for the offline access.
  • One of the purposes for the key manager 368 is to ensure that a secured document is still usable when the secured document is being accessed by an application that suddenly crashes.
  • the file key is then copied or a copy thereof is stored (cached) into the key manager 368 .
  • the file key is then used to decrypt the encrypted document.
  • a clear document is now available to the application. If the application crashes due to power outage or interfered by another application or OS, the file key in the header could be damaged. If no copy of the file key is available, the secured document may not be usable any more because the encrypted document would not be decrypted without the file key.
  • the reserved key maintained in the key manager 368 can be used to replace the damaged key and decrypt the encrypted document. After the user saves the file again, the file key is put back into the header.
  • Another purpose for the key manager 368 is to cache a user key or keys of an authenticated user.
  • This module is responsible for determining if a user accessing a secured document has been authenticated otherwise it will initiate a request for authentication with a local server or a central server.
  • the user verifying module 370 is always consulted before a permission is granted to the user seeking access to a secured document.
  • a user key or keys of an authenticated user are stored (cached) in the key manager 368 once the user is authenticated by the user verifying module 370 via the server.
  • the user key When a secured document is accessed, the user key must be retrieved from the key manager 368 to decrypt the encrypted security information in the header of the secured document.
  • the DSM 371 includes a cipher 372 that is used to generate a file/user key and encrypt/decrypt a document/header.
  • other securing means may be implemented in the DSM 371 , for example, a filter to block copying contents in a secured document into a non-secured document or a link from a secured document/original source to another document or recipient source.
  • Off-Line Access Manager 374
  • This module becomes effective only when the networked client machine is off the network, namely, the communication with a local server or a central server is not currently available. For example, a user is on the road and still needs to access some secured documents in a laptop computer. When five consultation is not available, the off-line access manager 374 is activated to ensure that the authorized user still can access the secured document but only for a limited time and perhaps with a limited privilege.
  • client module 362 in FIG. 3D lists some exemplary sub-modules according to one embodiment of the present invention and not every module in the server module 362 has to be implemented in order to practice the present invention.
  • client module 362 in FIG. 3D lists some exemplary sub-modules according to one embodiment of the present invention and not every module in the server module 362 has to be implemented in order to practice the present invention.
  • Those skilled in the art can understand that given the description herein, various combinations of the sub-modules, may achieve certain functions, benefits and advantages contemplated in the present invention.
  • keys that are used to secure files can use arbitrary strings.
  • Such keys are preferably public keys (also known as identity based public keys) that are used to encrypt files (or documents).
  • the public keys are arbitrary strings that embed or encode access restrictions (or access rules). The access restrictions are used to enforce access control policies.
  • Counterpart private keys are used to decrypt the files that have been previously encrypted with the public keys. The private keys can be generated to decrypt the portions of the files that have previously been encrypted with the public keys.
  • the public keys are based on arbitrary strings, the public keys and their private key counterparts are able to be generated in a decentralized manner (as well as in a centralized manner).
  • the ability to generate keys in a decentralized manner substantially eliminates key distribution burdens and facilitates off-line access to encrypted files.
  • the public keys which are based on arbitrary strings are preferably used as file keys to secure files. Often, the file keys are symmetric keys.
  • arbitrary strings can be used with other public keys besides file keys.
  • Such other public keys might, for example, be associated with user keys (also known as a group key when the key pertains to a group of users), clearance keys, or protection keys.
  • FIG. 4 is a block diagram of a file security system 400 according to one embodiment of the invention.
  • the file security system 400 includes an access server 402 and client machines 404 and 406 .
  • the access server 402 can pertain to a local server or a central server as noted above with respect to FIGS. 1A-1C .
  • the access server 402 couples to a network 408 , and the client machines 404 and 406 also couple to the network 408 .
  • the network 408 for example, can pertain to one or more of the Internet, a wide area network, a local area network, etc.
  • the access server 402 includes an access manager 410 and a key generator 412 with a rules engine.
  • the access manager 410 provides centralized control for management of user access to secured files.
  • the secured files can be associated with the access server, such as stored in a file store 414 , or associated with client machines 404 and 406 and stored in file stores such as a file store 416 or a file store 418 .
  • the access manager 410 communicates with the key generator 412 to decide whether a particular user is granted access to a secure file.
  • the key generator 412 within the rules engine evaluates the rules (e.g., access rules) that are associated with the secure file to be accessed.
  • the key generator 412 If the rules engine 412 determines that the access requested is permissible, then the key generator 412 generates a key that can be utilized in gaining access to the secure file.
  • the generated key is supplied to the access manager 410 .
  • the access manager 410 can either gain access to the secured file using the generated key or can supply the generated key to the appropriate client machine which in turn gains access to the secured file using the generated key.
  • the generated key can be referred to as a file key.
  • FIG. 5 is a block diagram of a distributed file security system 500 according to one embodiment of the invention.
  • the distributed file security system 500 distributes security operations to local client machines to distribute processing load as well as to reduce key transfer and distribution across networks.
  • the distributed file security system 500 includes an access server 502 and a representative client machine 504 coupled through a network 506 .
  • the access server 502 includes at least an access manager 508 that controls access to secure files managed by the distributed file security system 500 .
  • the client machine 504 couples to a file store 510 where secured files are stored.
  • the client machine 504 couples to a hardware (HW) card 512 (e.g., a smart card).
  • the hardware card 512 is, more generally, a peripheral device coupled to the client machine 504 .
  • the hardware card 512 includes an access controller 514 , a key generator with rules engine 516 and a key store 518 .
  • a rules string associated with access rules is used as a key (namely, public key) to access the secured file.
  • the key generator with rules engine 516 within the hardware card 512 receives the rule string and evaluates whether the user has sufficient privileges to access the secured file in view of the rules embedded within the rules string.
  • the access controller 514 produces a private key which is used to decrypt the secured file.
  • the private key can also be stored to the key store 518 .
  • the private key preferably resides within the hardware card 512 and thus is not transmitted beyond the hardware card 512 .
  • the private key is not stored on the client machine 504 , nor does the client key traverse the network 806 to be stored in the access server 502 .
  • FIG. 6 is a flow diagram of access rules based encryption processing 600 according to one embodiment of the invention.
  • the access rules based encryption processing 600 is, for example, performed by the access server 402 illustrated in FIG. 4 .
  • the access server 402 can represent a central server or a local server of a security system.
  • the access server 402 can also represent the server device 104 , 106 illustrated in FIGS. 1A and 1B .
  • Some or all of the access rules based encryption processing 600 can be performed at the client machines 404 , 406 of FIG. 4 or the client machines of FIGS. 1A-1C .
  • the access rules based encryption processing 600 initially obtains 602 access rules to be imposed. Namely, the access rules to be imposed are those access rules that are to be applied in securing a file. Next, a rules string is produced 604 in accordance with the access rules.
  • the rules string can follow a predetermined format to embed the access rules.
  • the rules string can vary, one example of a rules string is “9:00 am to 5:00 pm ⁇ Dec. 31, 2002” which encodes access rules that indicate that access to the associated secured file is only permitted between 9:00 am and 5:00 pm but only prior to Dec. 31, 2002. Another example is “10:00 am-2:00 pm on machine 10.200.255.213” which encodes access rules that indicate that access to the associated secured file is only permitted between 10:00 am and 2:00 pm from a machine having a specific network address.
  • the rules string can also include an access rule that limits access to the secured file to certain groups of users.
  • a group “human resources” could be used in an access rule to limit access to personnel files to only those users that are deemed in the human resources group.
  • Still another example is “Engineering, 9:00 am and 5:00 pm, Mon-Fri, off-line, MS-Word” which encodes access rules that indicate that access to the associated secured file is only permitted by user of the Engineering group, between 9:00 am to 5:00 pm, Monday through Friday, when off-line and when using MS-Word.
  • a public key is generated 606 based on the rules string.
  • the securing of the file is simplified in that the public key is derived from the rules string which in turn includes the access rules.
  • the public key is generated based on the rules string. Consequently, the public key is thus not supplied by a key generator (which would require distribution public/private key pairs).
  • at least a portion of the file is encrypted 608 using the public key.
  • the portion of the file being encrypted 608 is a data portion of the file.
  • FIG. 7 is a flow diagram of access rules based decryption processing 700 according to one embodiment of the invention.
  • the access rules based decryption processing 700 is performed in order to decrypt a file that has been previously encrypted (i.e., secured file).
  • a public key string associated with the secured file is obtained 702 .
  • access rules associated with the public key are identified 704 .
  • the access rules can be embedded in the public key string.
  • the access rules are then evaluated 706 .
  • a decision 708 determines whether the access rules are satisfied.
  • the access rules can be compared against access privileges associated with the requestor that desires access to the secured file.
  • the decision 708 determines that the access rules are not satisfied, then access to the secured file is denied 710 .
  • a private key is generated 712 based on the access rules and a master key.
  • the private key can be referred to as a file key.
  • the private key is decrypted 714 using the private key.
  • the portion of the secured file being decrypted 714 is a data portion of the secured file.
  • a master key is used to generate a private key. Hence, access to the master key must be restricted.
  • the master key is generated or regenerated based on gathered information.
  • the gathered information which may be considered a seed to generate a master key or the master key may itself be distributed among a central server, one or more local servers, and a local device (e.g., a smart card or simply a local client machine).
  • generation the master key or acquisition of the master key is shared among different machines, none could act alone to obtain the master key to proceed with the processes described herein.
  • a segment of the information is stored in the central server, another segment of the information is stored in a local server and a third segment of the information is stored in the local device.
  • the server the central or local server
  • the distributed segments of the information be gathered together to generate the master key or recover the master key.
  • the recovered or generated master key can, for example, also be configured to be valid for a certain period of time or for a fixed number of uses to enhance the security thereof.
  • FIG. 8 is a flow diagram of access rules based encryption processing 800 according to another embodiment of the invention.
  • the access rules based encryption 800 is, for example, performed by a distributed file security system, such as the distributed file security system 500 illustrated in FIG. 5 .
  • the access rules based encryption processing 800 initially obtains 802 access rules to be imposed when securing a file.
  • a rule string is produced 804 in accordance with the access rules.
  • the rules string can follow a predetermined format to embed the access rules.
  • a key block of the file to be encrypted (or secured) can then be obtained 806 .
  • a key block is a part of a header of a file format that includes one or more keys that are used to decrypt data within a data portion of the file format.
  • a public key for the key block is generated 808 based on the rule string.
  • the public key is able to be relatively easily generated given that it is based on the rules string. In other words, the public key can be generated without requiring the generation of a private/'key pair and without the need to distribute of such keys.
  • the key block of the file is then encrypted 810 using the public key.
  • the encrypted key block is then returned 812 to the requesting device.
  • the encrypted key block is then able to be affixed to the encrypted data portion of the secured file.
  • the encrypted key block can form part of the security information of the header portion of the secured file.
  • the data portion was previously encrypted using the one or more keys within the key block.
  • FIG. 9 is a flow diagram of access rules based decryption 900 according to one embodiment of the invention.
  • the access rules based decryption processing 900 is, for example, performed by a combination of an access server and a hardware card associated with a distributed data security system.
  • the access rules based decryption processing 900 initially obtains 902 a public key string associated with a secured file. Then, access rules associated with the public key are identified 904 . An encrypted key block is also obtained 906 . After the access rules have been identified 904 , the access rules within the public key are evaluated 908 . A decision 910 determines whether the access rules are satisfied. When the decision 910 determines that the access rules are satisfied, then a private key is generated 912 based on the access rules and a master key. Then, the encrypted key block is decrypted 914 to acquire a file key. Thereafter, the file key is utilized to decrypt 916 at least a portion of the secured file using the file key. In one embodiment, the at least the portion of the secured file pertains to a data portion of the secured file.
  • a decision 920 can determine whether to “lock down” the file security system to prevent further access to storage resources that store important security keys.
  • the decision 920 determines that a lock down should be performed, then subsequent access to the secured file, and perhaps other secured files maintained or managed by the same hardware card, are prevented 922 .
  • the secured file is not able to be being subsequently accessed 922 .
  • the operations 908 through 914 are performed internal to a tamper proof device, such as a hardware card (e.g., the hardware card 512 of FIG. 5 ).
  • a hardware card e.g., the hardware card 512 of FIG. 5
  • the master key and a key generation algorithm can be stored in the hardware card in a secure manner.
  • the private key being generated can also remain internal to the hardware card.
  • the master key can have one part (or segment) within the tamper proof device and another part (or segment) on a server or client machine.
  • a secure communication cannel can be used for communications between the various devices.
  • the results of the access rules based decryption 700 , 900 can be considered a clear file (i.e., decrypted file or decrypted data portion).
  • the clear file refers to the fact that the previously secured file is no longer secured, and is thus usable.
  • the clear file can be returned to the requestor. Nevertheless, the processing described above with respect to the access rules based decryption processing 700 , 900 shown in FIGS. 7 and 9 is typically preceded by authorization processing.
  • Authorization processing operates to authenticate the user seeking access to a secured file.
  • FIG. 10 illustrates flow diagrams of an authorization process 1000 according to one embodiment of the invention.
  • the authorization process 1000 begins with a decision 1002 that determines whether a request to access a secured file has been received. When the decision 1002 determines that such a request has not yet been received, the authorization process 1000 waits for such a request. In other words, the authorization process 1000 can be considered to be invoked when a request to access a secured file is received.
  • a decision 1004 determines whether the user and/or the client machine have been authenticated. Typically, the request is initiated by a user of a client machine. For security, both the user and the client machine are authenticated. When the decision 1004 determines that both the user and the client machine have not yet been authenticated, then authentication processing is performed 1006 .
  • the authentication processing that is performed 1006 serves to not only authenticate that the user is who the user claims he or she is, but also to determine that the client machine that the user is utilizing is one authorized to be used by the user. In the event that authentication were to be unsuccessful, the authorization process 1000 would end and the user would be unable to access the secured file. Additional details on authentication processing are provided below with reference to FIG. 11 .
  • a user key associated with the user is retrieved 1008 .
  • the user key can be retrieved 1008 from a storage location that is local or remote with respect to the computing device performing the authorization process 1000 .
  • part or all of the security information in the header portion of the secured file can be decrypted 1010 using the user key.
  • the secured file includes a header and a data portion.
  • the header can include, among other things, security information.
  • One component of the security information for the secured file is a file key.
  • the file key can be used to decrypt the data portion of the secured file.
  • FIG. 11 shows a flowchart of a user authentication process 1100 that may be implemented in a server, such as an access server, a central server or a local server.
  • a server such as an access server, a central server or a local server.
  • there are at least two situations that will call upon the user authentication process 1100 initial login to a networked client machine and first access to a secured document.
  • a client module in the client machine initiates a request that is transmitted to a server running a module providing the access control management to start the user authentication process 1100 .
  • the server awaits a request (e.g., authentication request) from the client machine.
  • a request e.g., authentication request
  • the server proceeds at a decision 1104 to determine if the user and the client machine from which the user attempts to access a secured document have already been authenticated. If both have already been authenticated, processing skips to operation 1112 .
  • the authentication processing 1100 continues when the decision 1104 determines that the user and the client machine have not already been authenticated.
  • the server may initiate a secured link with the client machine if both the server and the client machine are coupled to an open network, such link may be over HTTPS or supported through VPN. Alternatively, there may be a direct link between the client and the server if another authentication means is employed.
  • the server responds 1106 to the received request with an authentication response.
  • such response may be a dialog box to be displayed on the screen of the client machine, a command or other demand.
  • the response requires that credential information be provided by the user.
  • the credential information may be a set of username and password or biometric information of the user and must be received from the user.
  • a decision 1108 then causes the authentication processing 1100 to await for such credential information before the authentication processing 1100 may proceed.
  • a decision 1110 determines whether the user is authenticated.
  • the decision 1110 can determines whether the user is authenticated to access any secured files.
  • the authentication processing 1110 goes back to the beginning of the authentication processing 1100 to continue waiting for a request. In other words, the current request to access the secured documents or login to the system is abandoned. If the decision 1110 determines that the user is authenticated, the user is then recognized as being authentic. At the same time, the client machine can undergo a similar authentication by, perhaps, an IP address thereof, or a network card identification therein, or other means that uniquely identifies the client machine.
  • the user's access privilege is activated 1112 .
  • an activation of the user's access privilege may be a downloading of a file containing the access privilege to the client machine, a decryption of a local file containing the access privilege, or simply an activation of the user in a memory space of the server.
  • the user's access privilege(s) is readily accessible, thus permitting the user to access the secured documents from the authenticated client machine.
  • the secured document includes two encrypted portions, the header with encrypted security information and the encrypted data portion (i.e., the encrypted document).
  • the two parts in the secured document are encrypted respectively with two different keys, the file key and the user key.
  • the two encrypted portions may be encrypted again with another key (or use the same user key).
  • the invention also facilitates sharing secured files between different organizations.
  • a unique company identifier can be encoded into the rules string and thus become part of the public key of the company.
  • a user key (a private key) of the company can be generated locally to access the secured file.
  • the encrypted access rules can be integrated with other sets of the encrypted access rules in a rules block as illustrated in FIG. 3A . As such, access from one user or group will not affect other users or groups but the other users or groups will see perhaps an updated version of the encrypted document.
  • the invention is preferably implemented by software or a combination of hardware and software, but can also be implemented in hardware.
  • the invention can also be embodied as computer readable code on a computer readable medium.
  • the computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, DVDs, magnetic tape, optical data storage devices, and carrier waves.
  • the computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.
  • One advantage of the invention is that public keys used to encrypt files are not generated prior to protection. Consequently, the system does not need to generate keys in advance and then store and distribute them.
  • Another advantage of the invention is that the public keys encode rules that provide access restrictions. The rules (access rules) are also used to generate the private keys, which protects the rules from being modified.
  • Still another advantage of the invention is that off-line access to protected (secured) documents is facilitated.
  • Yet still another advantage of the invention is that protected files are able to be easily shared between groups within a particular organization as well as between disparate organizations.

Abstract

Improved system and approaches for decentralized key generation are disclosed. The keys that can be generated include both public keys and private keys. The public keys are arbitrary strings that embed or encode access restrictions. The access restrictions are used to enforce access control policies. The public keys are used to encrypt some or all portions of files. The private keys can be generated to decrypt the portions of the files that have been encrypted with the public keys. By generating keys in a decentralized manner, not only are key distribution burdens substantially eliminated but also off-line access to encrypted files is facilitated.

Description

    CROSS-REFERENCE TO RELATED APPLICATIONS
  • This application is a Continuation-In-Part (CIP) of U.S. patent application Ser. No. 10/075,194, filed Feb. 12, 2002, and entitled “SYSTEM AND METHOD FOR PROVIDING MULTI-LOCATION ACCESS MANAGEMENT TO SECURED ITEMS,” which is hereby incorporated by reference for all purposes, and which claims priority of U.S. Provisional Application No. 60/339,634, filed Dec. 12, 2001, and entitled “PERVASIVE SECURITY SYSTEMS,” which is hereby incorporated by reference for all purposes.
  • This application is also related to: (i) U.S. application Ser. No. 10/186,203, filed Jun. 26, 2002, and entitled “METHOD AND SYSTEM FOR IMPLEMENTING CHANGES TO SECURITY POLICIES IN A DISTRIBUTED SECURITY SYSTEM,” which is hereby incorporated by reference for all purposes; (ii) U.S. patent application Ser. No. 10/206,737, filed Jul. 26, 2002, and entitled “METHOD AND SYSTEM FOR UPDATING KEYS IN A DISTRIBUTED SECURITY SYSTEM,” which is hereby incorporated by reference for all purposes; (iii) U.S. patent application Ser. No. 10/159,537, filed May 31, 2002, and entitled “METHOD AND APPARATUS FOR SECURING DIGITAL ASSETS,” which is hereby incorporated by reference for all purposes; and (iv) U.S. patent application Ser. No. 10/074,825, filed Feb. 12, 2002, and entitled “METHOD AND APPARATUS FOR ACCESSING SECURED ELECTRONIC DATA OFF-LINE,” which is hereby incorporated by reference for all purposes.
  • BACKGROUND OF THE INVENTION
  • 1. Field of the Invention
  • The present invention relates to security systems for data and, more particularly, to security systems that protect data in an inter/intra enterprise environment.
  • 2. Description of Related Art
  • The Internet is the fastest growing telecommunications medium in history. This growth and the easy access it affords have significantly enhanced the opportunity to use advanced information technology for both the public and private sectors. It provides unprecedented opportunities for interaction and data sharing among businesses and individuals. However, the advantages provided by the Internet come with a significantly greater element of risk to the confidentiality and integrity of information. The Internet is an open, public and international network of interconnected computers and electronic devices. Without proper security means, an unauthorized person or machine may intercept any information traveling across the Internet and even get access to proprietary information stored in computers that interconnect to the Internet, but are otherwise generally inaccessible by the public.
  • There are many efforts in progress aimed at protecting proprietary information traveling across the Internet and controlling access to computers carrying the proprietary information. Cryptography allows people to carry over the confidence found in the physical world to the electronic world, thus allowing people to do business electronically without worries of deceit and deception. Every day hundreds of thousands of people interact electronically, whether it is through e-mail, e-commerce (business conducted over the Internet), ATM machines, or cellular phones. The perpetual increase of information transmitted electronically has lead to an increased reliance on cryptography.
  • One of the ongoing efforts in protecting the proprietary information traveling across the Internet is to use one or more cryptographic techniques to secure a private communication session between two communicating computers on the Internet. The cryptographic techniques provide a way to transmit information across an unsecure communication channel without disclosing the contents of the information to anyone eavesdropping on the communication channel. Using an encryption process is a cryptographic technique whereby one party can protect the contents of the data in transit from access by an unauthorized third party, yet the intended party can read the data using a corresponding decryption process.
  • A firewall is another security measure that protects the resources of a private network from users of other networks. However, it has been reported that many unauthorized accesses to proprietary information occur from the inside, as opposed to from the outside. An example of someone gaining unauthorized access from the inside is when restricted or proprietary information is accessed by someone within an organization who is not supposed to do so. Due to the open nature of the Internet, contractual information, customer data, executive communications, product specifications, and a host of other confidential and proprietary intellectual property remain available and vulnerable to improper access and usage by unauthorized users within or outside a supposedly protected perimeter.
  • Many businesses and organizations have been looking for effective ways to protect their proprietary information. Typically, businesses and organizations have deployed firewalls, Virtual Private Networks (VPNs), and Intrusion Detection Systems (IDS) to provide protection. Unfortunately, these various security means have been proven insufficient to reliably protect proprietary information residing on private networks. For example, depending on passwords to access sensitive documents from within often causes security breaches when the password of a few characters long is leaked or detected. Consequently, various cryptographic means are deployed to provide restricted access to electronic data in security systems.
  • Various security criteria, such as encryption or decryption keys, are often used to facilitate the restricted access in the security systems. However, prolonged use of the security criteria, if not updated, can impose threats to the security of the protected data. While periodic updates to keys can help preserve security, the generation and distribution of key (such as in a network-based system) is a significant burden to system resources. When the system maintains a large number of keys for numerous file and users, the demand of system resources is even more taxing. Therefore, there is a need to provide more effective ways to utilize the security criteria (e.g. the keys) for security systems to secure and protect resources.
  • SUMMARY OF THE INVENTION
  • The invention relates to improved approaches for decentralized key generation. The keys that can be generated include both public keys and private keys. The public keys are arbitrary strings that embed or encode access restrictions. The access restrictions are used to enforce access control policies. The public keys are used to encrypt some or all portions of files. The private keys can be generated to decrypt the portions of the files that have been encrypted with the public keys. By generating keys in a decentralized manner, not only are key distribution burdens substantially eliminated but also off-line access to encrypted files is facilitated.
  • The invention can be implemented in numerous ways, including as a method, system, device, and computer readable medium. Several embodiments of the invention are discussed below.
  • As a method for encrypting a file, one embodiment of the invention includes at least the acts of: obtaining access rules to be imposed; producing a rules string in accordance with the access rules; generating a public key based on the rules string; and encrypting at least a portion of the file using the public key.
  • As another method for encrypting a file, one embodiment of the invention includes at least the acts of: identifying access rules to be imposed; producing a rules string in accordance with the access rules; obtaining a key block of the file to be encrypted, the file including at least the key block and a data block; generating a public key for the key block based on the rules string; and encrypting the key block portion of the file using the public key.
  • As a method for decrypting a secured file that has been previously encrypted, one embodiment of the invention includes at least the acts of: obtaining a key string associated with the secured file to be decrypted; identifying access rules associated with the key string; evaluating the access rules to determine whether a user requesting access to the secured file is permitted access to the secured file; denying access to the secured file when said evaluating determines that the access rules do not permit the user to access the secured file; generating a private key based on the access rules and a master key when said evaluating determines that the access rules permit the user to access the secured file; and decrypting, following said generating, at least a portion of the secured file for access thereto by the user through use of the private key.
  • As another method for decrypting a secured file that has been previously encrypted, one embodiment of the invention includes at least the acts of: obtaining a key string associated with the secured file to be decrypted; identifying access rules associated with the key string; obtaining an encrypted key block of the secured file; evaluating the access rules to determine whether a user requesting access to the secured file is permitted access to the secured file; denying access to the secured file when said evaluating determines that the access rules do not permit the user to access the secured file; generating a private key based on the access rules and a master key when said evaluating determines that the access rules permit the user to access the secured file; decrypting, following said generating, the encrypted key block to obtain a file key; and thereafter decrypting at least a portion of the secured file for access thereto by the user through use of the file key.
  • As a computer readable medium including at least computer program code for encrypting a file, one embodiment of the invention includes at least: computer program code for obtaining access rules to be imposed; computer program code for producing a rules string in accordance with the access rules; computer program code for generating a public key based on the rules string; and computer program code for encrypting at least a portion of the file using the public key.
  • As a computer readable medium including at least computer program code for decrypting a secured file that has been previously encrypted, one embodiment of the invention includes at least: computer program code for obtaining a key string associated with the secured file to be decrypted; computer program code for identifying access rules associated with the key string; computer program code for evaluating the access rules to determine whether a user requesting access to the secured file is permitted access to the secured file; computer program code for denying access to the secured file when said evaluating determines that the access rules do not permit the user to access the secured file; computer program code for generating a private key based on the access rules and a master key when said evaluating determines that the access rules permit the user to access the secured file; and computer program code for decrypting at least a portion of the secured file for access thereto by the user through use of the private key.
  • Other objects, features, and advantages of the present invention will become apparent upon examining the following detailed description of an embodiment thereof, taken in conjunction with the attached drawings.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings wherein:
  • FIG. 1A shows a basic system configuration in which the invention may be practiced in accordance with an embodiment thereof.
  • FIG. 1B shows another system configuration in which the invention may be practiced in accordance with an embodiment thereof.
  • FIG. 1C shows still another system configuration in which the invention may be practiced in accordance with an embodiment thereof.
  • FIG. 1D shows internal construction blocks of a computing device in which the invention may be implemented and executed.
  • FIG. 2A is a block diagram of securing a created document according to one embodiment of the invention.
  • FIG. 2B illustrates an exemplary structure of a secured document including a header and an encrypted portion.
  • FIG. 3A illustrates a representative data structure of a secured file including a header and an encrypted data portion according to one embodiment of the invention.
  • FIG. 3B is a functional block diagram of a server device in accordance with one embodiment of the invention.
  • FIG. 3C is a functional block diagram of a local server device according to one embodiment of the invention.
  • FIG. 3D is a functional block diagram of a client machine according to one embodiment of the invention.
  • FIG. 4 is a block diagram of a file security system according to one embodiment of the invention.
  • FIG. 5 is a block diagram of a distributed file security system according to one embodiment of the invention.
  • FIG. 6 is a flow diagram of access rules based encryption processing according to one embodiment of the invention.
  • FIG. 7 is a flow diagram of access rules based decryption processing according to one embodiment of the invention.
  • FIG. 8 is a flow diagram of access rules based encryption processing according to another embodiment of the invention.
  • FIG. 9 is a flow diagram of access rules based decryption according to another embodiment of the invention.
  • FIG. 10 illustrates flow diagrams of an authorization process according to one embodiment of the invention.
  • FIG. 11 shows a flowchart of a user authentication process that may be implemented in a server, such as an access server, a central server or a local server.
  • DETAILED DESCRIPTION OF THE INVENTION
  • The invention relates to improved approaches for decentralized key generation. The keys that can be generated include both public keys and private keys. The public keys are arbitrary strings that embed or encode access restrictions. The access restrictions are used to enforce access control policies. The public keys are used to encrypt some or all portions of files. The private keys can be generated to decrypt the portions of the files that have been encrypted with the public keys. By generating keys in a decentralized manner, not only are key distribution burdens substantially eliminated but also off-line access to encrypted files is facilitated. The present invention is particularly suitable in an enterprise environment.
  • As used herein, a user may mean a human user, a software agent, a group of users, a member of the group, a device and/or application. Besides a human user who needs to access a secured document, a software application or agent sometimes needs to access secured files in order to proceed. Accordingly, unless specifically stated, the “user” as used herein does not necessarily pertain to a human being.
  • Secured files are files that require one or more keys, passwords, access privileges, etc. to gain access to their content. According to one aspect of the present invention, the security is provided through encryption and access rules. The files, for example, can pertain to documents, multimedia files, data, executable code, images and text. In general, a secured file can only be accessed by authenticated users with appropriate access rights or privileges. Each secured file is provided with a header portion and a data portion, where the header portion contains, or points to, security information. The security information is used to determine whether access to associated data portions of secured files is permitted.
  • In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will become obvious to those skilled in the art that the present invention may be practiced without these specific details. The description and representation herein are the common meanings used by those experienced or skilled in the art to most effectively convey the substance of their work to others skilled in the art. In other instances, well-known methods, procedures, components, and circuitry have not been described in detail to avoid unnecessarily obscuring aspects of the present invention.
  • Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Further, the order of blocks in process flowcharts or diagrams representing one or more embodiments of the invention do not inherently indicate any particular order nor imply any limitations in the invention.
  • Embodiments of the present invention are discussed herein with reference to FIGS. 1A-11. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments.
  • FIG. 1A shows a basic system configuration in which the present invention may be practiced in accordance with one embodiment thereof. Documents or files may be created using an authoring tool executed on a client computer 100, which may be a desktop computing device, a laptop computer, or a mobile computing device. Exemplary authoring tools may include application programs such as Microsoft Office (e.g., Microsoft Word, Microsoft PowerPoint, and Microsoft Excel), Adobe FrameMaker and Adobe Photoshop.
  • According to one embodiment, the client computer 100 is loaded with a client module that is capable of communicating with a server 104 or 106 over a data network (e.g., the Internet or a local area network). According to another embodiment, the client computer 100 is coupled to the server 104 through a private link. As will be further explained below, a document or file created by an authoring tool can be secured by the client module. The client module, when executed, is configured to ensure that a secured document is secured at all times in a store (e.g., a hard disk or other data repository). The secured documents can only be accessed by users with proper access privileges. In general, an access privilege or access privileges for a user may include, but not be limited to, privileges pertaining to viewing, copying, printing, editing, transferring, uploading/downloading, and location.
  • According to one embodiment, a created document is caused to go through an encryption process that is preferably transparent to a user. In other words, the created document is encrypted or decrypted under the authoring application so that the user is not aware of the process. A key (referred to herein as a user key) can be used to retrieve a file key to decrypt an encrypted document. Typically, the user key is associated with an access privilege for the user or a group of users. For a given secured document, only a user with a proper access privilege can access the secured document.
  • In one setting, a secured document may be uploaded via the network 110 from the computer 100 to a computing or storage device 102 that may serve as a central repository. Although not necessary, the network 110 can provide a private link between the computer 100 and the computing or storage device 102. Such link may be provided by an internal network in an enterprise or a secured communication protocol (e.g., VPN and HTTPS) over a public network (e.g., the Internet). Alternatively, such link may simply be provided by a TCP/IP link. As such, secured documents on the computer 100 may be remotely accessed.
  • In another setting, the computer 100 and the computing or storage device 102 are inseparable, in which case the computing or storage device 102 may be a local store to retain secured documents or receive secured network resources (e.g., dynamic Web contents, results of a database query, or a live multimedia feed). Regardless of where the secured documents or secured resources are actually located, a user, with proper access privilege, can access the secured documents or resources from the computer 100 or the computing or storage device 102 using an application (e.g., Internet Explorer, Microsoft Word or Acrobat Reader).
  • The server 104, also referred to as a local server, is a computing device coupled between a network 108 and the network 110. According to one embodiment, the server 104 executes a local version of a server module. The local version is a localized server module configured to service a group of designated users or client computers, or a location. Another server 106, also referred to as a central server, is a computing device coupled to the network 108. The server 106 executes the server module and provides centralized access control management for an entire organization or business. Accordingly, respective local modules in local servers, in coordination with the central server, form a distributed mechanism to provide distributed access control management. Such distributed access control management ensures the dependability, reliability and scalability of centralized access control management undertaken by the central server for an entire enterprise or a business location.
  • FIG. 1B shows another system configuration in which the invention may be practiced in accordance with an embodiment thereof. Here, the configuration employs a central server and local servers. The configuration may correspond to a large enterprise having multiple geographic locations or offices. A central server 106 maintains a database managing the access privileges and the access rules in the entire enterprise. One of the features in this configuration is the underlying capability to provide fault tolerance and efficient AC (Access Control) management for a large group of users. Instead of having the central server 106 performing the AC management for each of the users at one single location, a number of local servers 104 (e.g., 104-A, 104-B, . . . and 104-N) are employed in a distributed manner to service the individual locations or offices. Each of local servers 104 executes a local module derived or duplicated from the server module being executed at the central server 106 to manage those users who are local to respective local servers 104. The central server 106 can centralize the AC management in addition to managing the users if necessary.
  • According to one embodiment, a local module can be a customized version of the server module that runs efficiently for only a few locations or a group of users. For example, a local server 104-A is only responsible for the users or computers 102-A in location A, while a local server 104-B is only responsible for the users or computers 102-B in location B. As a result, even if the central server 106 has to be taken down for maintenance or is not operative at the time a user needs to access secured documents, the access control will not be disrupted. The detailed operation of the local servers 104 in cooperation with the central server 106 will be further described below.
  • According to another embodiment, a local module is a replicated version of the server module and exchanges any updates with the server module when connected (e.g., periodically or at request). Depending on implementation, part or all of the server module can be duplicated in a local server to ensure that communications with users or their client machines are efficient and fault tolerance. As a result, even if the central server 106 has to be taken down for maintenance or is not operative at the time a user needs to access secured documents, the access control will not be disruptive. For example, in such a situation, any of the local servers 104 can step up and take the place of the central server. When the central server 106 is running or communicating with the local servers 104, information collected at the respective local servers about the users or their activities is sent back to the central server 106. The detailed operation of the local servers 104 in cooperation with the central server 106 in this regard will also be further provided below.
  • FIG. 1C shows still another system configuration in which the invention may be practiced in accordance with an embodiment thereof. This configuration is suitable for a small group of users. In this configuration, no local servers are employed. A server computer 112 is loaded with the server module and each of the users or terminal computers 116 (only one is shown therein) is loaded with a client module. The users or the terminal computers 16 couple to the server computer 112 through a local area network. The server computer 112 performs the AC management for each of the users or the terminal computers 116.
  • FIG. 1D shows internal construction blocks of a computing device 118 in which one embodiment of the present invention may be implemented and executed. The computing device 118 may correspond to a client device (e.g., computer 100, computing or storage device 102 in FIG. 1A) or a server device (e.g., server 104, 106 in FIG. 1A). As shown in FIG. 1B, the computing device 118 includes a central processing unit (CPU) 122 interfaced to a data bus 120. The CPU 122 executes instructions to process data and perhaps manage all devices and interfaces coupled to data bus 120 for synchronized operations. The instructions being executed can, for example, pertain to drivers, operating system, utilities or applications. Device interface 124 may be coupled to an external device, such as the computing device 102 of FIG. 1A; hence, the secured documents therefrom can be received into memory 132 or storage 136 through data bus 120. Also interfaced to data bus 120 is a display interface 126, a network interface 128, a printer interface 130 and a floppy disk drive interface 138. Generally, a client module, a local module or a server module of an executable version of one embodiment of the present invention can be stored to storage 136 through floppy disk drive interface 138, network interface 128, device interface 124 or other interfaces coupled to data bus 120. Execution of such module by the CPU 122 can cause the computing device 118 to perform as desired in the present invention. In one embodiment, the device interface 124 provides an interface for communicating with a capturing device 125 (e.g., a fingerprint sensor, a smart card reader or a voice recorder) to facilitate the authentication of a user of the computing device 118.
  • Main memory 132, such as random access memory (RAM), is also interfaced to data bus 120 to provide the CPU 122 with instructions and access to memory storage 136 for data and other instructions. In particular, when executing stored application program instructions, such as for document securing or document accessing, the CPU 122 is caused to manipulate the data to achieve results contemplated by the program instructions. Read-only memory (ROM) 134 is provided for storing executable instructions, such as a basic input/output operation system (BIOS) for operation of keyboard 140, display 126 and pointing device 142 which may be present.
  • In one embodiment, the computing device 118 is capable of storing secured items (e.g., secured files) in the main memory 132 or the storage 136. The main memory 132 provides non-persistent (i.e., volatile) storage for the secured items and the storage 136 provides persistent (i.e., non-volatile) storage for the secured items. Hence, the computing or storage device 102, or more particularly, the main memory 132 and/or the storage 136, can act as a storage device for the secured items.
  • Referring now to FIG. 2A, a block diagram of securing a created document 200 is shown according to one embodiment of the invention. For example, the created document 200 is a created file. After the document 200 is created, edited or opened with an application or authoring tool (e.g., Microsoft Word), upon an activation of a command, such as “Save,” “Save As” or “Close”, or automatic saving invoked by an operating system, the application itself or an approved application, the created document 200 is caused to undergo a securing process 201. The securing process 201 starts with an encryption process 202, namely the document 200 that has been created or is being written into a store is encrypted by a cipher (e.g., an encryption process) with a file key (i.e., a cipher key), in other words, the encrypted data portion 212 could not be opened without the file key. For the purpose of controlling the access to the contents in the document 200 or the resultant secured file 208, the file key or keys may be the same or different keys for encryption and decryption and are included as part of security information contained in or pointed to by a header 206. The file key or keys, once obtained, can be used to decrypt the encrypted data portion 212 to reveal the contents therein.
  • To ensure that only authorized users or members of an authorized group can access the secured file 208, a set of access rules 204 for the document 200 is received or created and associated with the header 206. In general, the access rules 204 determine or regulate who and/or how the document 200, once secured, can be accessed. In some cases, the access rules 204 also determine or regulate when or where the document 200 can be accessed.
  • In addition, security clearance information 207 can be added to the header 206 if the secured file 208 is classified. In general, the security clearance information 207 is used to determine a level of access privilege or security level of a user that is attempting to access the contents in the secured file 208. For example, a secured file may be classified as “Top secret”, “Secret”, “Confidential”, and “Unclassified”. According to one embodiment, the security clearance information 207 includes another layer of encryption of the file key with another key referred to herein as a clearance key. An authorized user must have a clearance key of proper security level in addition to an authenticated user key and proper access privilege to retrieve the file key. As used herein, a user key or a group key is a cipher key associated with an authenticated user and may be used to access a secured file or secure a file, or create a secured file. Additional detail on obtaining such a user key upon a user being authenticated is provided in U.S. patent application Ser. No. 10/074,194, which is hereby incorporated herein by reference.
  • According to another embodiment, the security clearance information 207 includes a set of special access rules to guard the file key. The retrieval of the file key requires that the user pass an access rule measurement. Since access privilege of a user may be controlled via one or more system parameters (e.g., rules or policies), the access rule measurement can determine if the user has sufficient access privilege to retrieve the file key in conjunction with the corresponding user key.
  • In accordance with the security clearance information 207, a user may be assigned a hierarchical security clearance level based on, perhaps, a level of trust assigned to the user. A level of trust implies that one user may be more trusted than another and hence the more trusted user may access more classified files. Depending on implementation, a level of trust may be based on job responsibility of the user or a role of the user in a project or an organization background checks, psychological profiles, length of service, etc. In any case, a level of trust assigned to the user augments additional aspect to the access privilege of the user such that the user must have proper security clearance to access a classified secured file even if the user is permitted by the access rules to access the file.
  • In general, a header is a file structure, preferably small in size, and includes, or perhaps links to, security information about a resultant secured document. Depending on implementation, the security information can be entirely included in a header or pointed to by a pointer that is included in the header. The security information further includes the file key and/or one or more clearance keys, in some cases, an off-line access permit (e.g., in the access rules) should such access be requested by an authorized user. The security information is then encrypted by a cipher (i.e., an encryption/decryption scheme) with a user key associated with an authorized user to produce encrypted security information 210. The encrypted header 206, if no other information is added thereto, is attached to or integrated with the encrypted data portion 212 to generate the resultant secured file 208. In a preferred embodiment, the header is placed at the beginning of the encrypted document (data portion) to facilitate an early detection of the secured nature of a secured file. One of the advantages of such placement is to enable an access application (i.e., an authoring or viewing tool) to immediately activate a document securing module (to be described where it deems appropriate) to decrypt the header if permitted. Nevertheless, there is no restriction as to where the encrypted header 206 is integrated with the encrypted data portion 212.
  • It is understood that a cipher may be implemented based on one of many available encryption/decryption schemes. Encryption and decryption generally require the use of some secret information, referred to as a key. For some encryption mechanisms, the same key is used for both encryption and decryption; for other mechanisms, the keys used for encryption and decryption are different. In any case, data can be encrypted with a key according to a predetermined cipher (i.e., encryption/decryption) scheme. Examples of such schemes may include, but not be limited to, Data Encryption Standard algorithm (DES), Blowfish block cipher and Twofish cipher. Therefore, the operations of the present invention are not limited to a choice of those commonly-used encryption/decryption schemes. Any cipher scheme that is effective and reliable may be used. Hence, the details of a particular scheme are not further discussed herein so as to avoid obscuring aspects of the present invention.
  • In essence, the secured document 208 includes two parts, the encrypted data portion 212 (i.e., encrypted version of the document itself) and the header 210 that may point to or include encrypted security information for the secured document 208. To access the contents in the encrypted data portion 212, one needs to obtain the file key to decrypt the encrypted data portion 212. To obtain the file key, one needs to be authenticated to get a user or group key and pass an access test in which at least the access rules in the security information are measured against the user's access privilege (i.e., access rights). If the secured file is classified, it further requires a security level clearance on the user. In general, the security clearance level of the user must be high enough before the file key can be retrieved.
  • FIG. 2B illustrates an exemplary structure of a secured document 220 including a header 222 and an encrypted portion 224. The header 222 includes a security information block 226 having encrypted security information that essentially controls the access to the encrypted document 224. In a certain implementation, the header 222 includes a flag 227 (e.g., a predetermined set of data) to indicate that the document 220 is secured. The security information block 226 includes one or more user IDs 228, access rules 229, at least one file key 280 and other information 231. The user IDs 228 maintain a list of authorized users who may be measured against the access rules 229 before the file key 230 can be retrieved. The access rules 229 determine at least who and how the encrypted document 224 can be accessed. Depending on an implementation, the other information 231 may be used to include other information facilitating a secure access to the encrypted document 224, the example may include version numbers or author identifier.
  • In general, a document is encrypted with a cipher (e.g., a symmetric or asymmetric encryption scheme). Encryption is the transformation of data into a form that is impossible to read without appropriate knowledge (e.g., a key). Its purpose is to ensure privacy by keeping information hidden from anyone to whom it is not intended, even those who have access to other encrypted data. Decryption is the reverse of encryption. Encryption and decryption generally require the use of some secret information, referred to as a key. For some encryption mechanisms, the same key is used for both encryption and decryption; for other mechanisms, the keys used for encryption and decryption are different. For the purpose of controlling the access to the document, the key or keys, referred collectively to as a file key, may be the same or different keys for encryption and decryption and are preferably included in the security information (e.g., security information block 226) contained in or pointed to by the header (header 222) and, once obtained, can be used to decrypt the encrypted document.
  • To ensure that the key is not to be retrieved or accessible by anyone, the key itself is guarded by the access privileges and rules. If a user requesting the document has the adequate access privileges given the requirement of the access rules, the key will be retrieved so as to permit the decryption of the encrypted document.
  • To ensure that the security information or the header (if no flag is implemented) is not readily revealed, the header itself can be encrypted with a cipher. Depending on an exact implementation, the cipher for the header may or may not be identical to the one used for the document. The key (referred to as a user key) to decrypt the encrypted header can, for example, be stored in a local store of a terminal device (e.g., client computer) and activated only when the user associated with it is authenticated. As a result, only an authorized user can access the secured document.
  • Optionally, the two encrypted portions (i.e., the encrypted header and the encrypted document) can be encrypted again and only decrypted by a user key. In another option, the encrypted portions (either one or all) can be error checked by error checking portion 225, such as using a cyclical redundancy check to ensure that no errors have been incurred to the encrypted portion(s) or the secured document 220.
  • In general, each of the users in a security system is assigned a user key or user keys (e.g., a user public key and a private key). In some cases, the user key is also referred to as a group key if a user is a member of group (e.g., Engineering) that has uniform access privilege. In one application, the user public key is used to encrypt some or all of the security information in the header and the user private key is used to get into the security information or header for the purpose of retrieving the file or document key so as to decrypt the encrypted data portion or the encrypted document. Unless specified otherwise, a user key herein indicates either or both of the user public key and the private key or a security key that is needed in the system to retrieve the file key to decrypt the encrypted data portion.
  • In a typical enterprise environment, different users may have different access privileges, some may access all secured files while others may access some of the secured files with restricted actions (i.e., printing, reading or editing, but not forwarding). Whether a user can ultimately achieve the access to the encrypted data portion in a secured file is controlled by the access rules or additional key(s) in the security information of the header. Limited by a user's access privilege, a user key associated with the user may facilitate access to all secured files.
  • FIG. 3A illustrates a representative data structure of a secured file 300 including a header 302 and an encrypted data portion 304 according to one embodiment of the invention. The secured file 300 is secured by access rules and use of encryption. A user must possess a user key, a protection key, a file key and sometimes a clearance key in order to access the secured file 300. Depending on implementation, the header 302 may or may not include a flag or signature 306. In one case, the signature 306 is used to facilitate the detection of the security nature of a secured file among other files. The header 302 includes a file key block 308, a key block 310 and a rule block 312. The file key block 308 includes a file key 309 that is encrypted by a cipher with a protection key 320 (i.e., a doc-key key sometimes) and further with a clearance key 322 associated with a user that attempts to access the secured file 300. Alternatively, the file key 309 is encrypted with the clearance key 322 and then the protection key 320. The protection key 320 is encrypted and stored in the key block 310. In general, the key block 310 has an encrypted version of the protection key 320 and can be only accessible by designated user(s) or group(s). There may be more than one key blocks 310 in a header, wherein three key blocks are shown in FIG. 3A. To recover or retrieve the protection key 320, a designated user must have proper access privilege to pass an access rule test with the embedded access rules in the rule block 312.
  • All access rules are encrypted with a user key (e.g., a public user key) and stored in the rule block 312. A user attempting to access the secured file uses must have a proper user key (e.g., a private user key) to decrypt the access rules in the rule block 312. The access rules are then applied to measure the access privileges of the user. If the user is permitted to access the secured file in view of the access rules, the protection key 320 in the key block 310 is retrieved to retrieve the file key 309 so as to access the encrypted data portion 304. However, when it is detected that the secured file is classified, which means that the file key can not be retrieved with only the protection key, the user must posses a clearance key. Only the user that has the clearance key and the retrieved protection key 320 is able to retrieve the file key 309 and proceed with the decryption of the encrypted data portion 304.
  • According to one embodiment, the encrypted data portion 304 is produced by encrypting a file that is non-secured. For example, a non-secured document can be created by an authoring tool (e.g., Microsoft Word). The non-secured document is encrypted by a cipher with the file key. The encryption information and the file key are then stored in the security information, namely, the file key block 308 of the header 302.
  • According to another embodiment, the non-secured document (data) is encrypted using the following aspects, a strong encryption using a CBC mode, a fast random access to the encrypted data, and an integrity check. To this end, the data is encrypted in blocks. The size of each block may be a predetermined number or specific to the document. For example, the predetermined number may be a multiple of an actual encryption block size used in an encryption scheme. One of the examples is a block cipher (i.e., a type of symmetric-key encryption algorithm that transforms a fixed-length block of plaintext (unencrypted text) data into a block of ciphertext (encrypted text) data of the same length. This transformation takes place under the action of a cipher key (i.e., a file key). Decryption is performed by applying the reverse transformation to the ciphertext block using another cipher key or the same cipher key used for encryption. The fixed length is called the block size, such as 64 bits or 128. Each block is encrypted using a CBC mode. A unique initiation vector (IV) is generated for each block.
  • Other encryption of the non-secured data can be designed in view of the description herein. In any case, the encryption information and the file key are then stored in the security information. One aspect of the present invention is that the integration of a header and the encrypted data portion will not alter the original meaning of the data that is otherwise not secured. In other words, a designated application may still be activated when a secured file is selected or “clicked”. For example, a document “xyz.doc”, when selected, will activate an authoring tool, e.g., Microsoft Word, commonly seen in a client machine. After the document “xyz.doc” is secured in accordance with the present invention, the resultant secured file is made to appear the same, “xyz.doc” that still can activate the same authorizing tool, except now the secured file must go through a process to verify that a user is authenticated, the user has the proper access privilege and (if imposed) sufficient security clearance.
  • Further, with the protection key, the file key can be updated without having to modify the key-blocks. For example, with respect to FIG. 3A, the file key 309 in the file key block 30 can be updated without having to modify the key-blocks 310. One of the features in the structure shown in FIG. 3A is that the underlying mechanism facilitates the updating and management of the file key.
  • In the above-described embodiment in FIG. 3A, the access rules were encrypted with a user's public key. Those skilled in the art can appreciate that the access rules can be encrypted in other ways. For example, the access rules may be also encrypted with a file encryption key (i.e., the file key) or the protection key. In this case, the protection key is encrypted with a user's public key or together with a clearance key associated with the user if a subject secured file is secured. Alternatively, instead of retrieving the protection key after the access rules are successfully measured against access privilege of the user attempting to access a secured file, the protection key can be retrieved first with a user's private key. The protection key can be used to retrieve the access rules that are subsequently used to measure against the access privilege of the user if the protection key was used to encrypt the access rules. If the user is permitted to access the contents in the file, the file key is then retrieved with the protection key (or together with the clearance key). Alternatively, right after the protection key is retrieved, the protection key (or together with the clearance key) is used to retrieve the file key. The file key is then to retrieve the access rules that are subsequently used to measure against the access privilege of the user. In any case, if the user is determined have sufficient access privilege in view of all access policies, if there are any, the retrieved file key can be used to continue the decryption of the encrypted data portion.
  • It should be noted that the header in a secured document may be configured differently than noted above without departing from the principles of the present invention. For example, a secured document may include a header with a plurality of encrypted headers, each can be accessible only by one designated user or a group users. Alternatively, a header in a secured document may include more than one set of security information or pointers thereto, each set being for one designated user or a group of users while a single file key can be used by all. Some or all of the access rules may be viewed or updated by users who can access the secured document.
  • In another alternative representative data structure for a secured file, the header can include at least one pointer which points to a remote data structure stored in a storage device. The remote data structure can store some or all of the security information, thereby shortening the size of the header and improving manageability of security information. The storage device is typically a local storage device. In other words, the alternative data structure and the remote data structure are typically stored on a common machine (e.g., desktop or portable computer). The data structure stores security information. Additional details on the alternative data structure can be found in U.S. application Ser. No. 10/132,712 (Att. Dkt.: SSL1P005/SS-14), filed Apr. 26, 2002, and entitled “METHOD AND SYSTEM FOR PROVIDING MANAGEABILITY TO SECURITY INFORMATION FOR SECURED ITEMS,” which is hereby incorporated herein by reference.
  • According to one embodiment, the access rules are present in a descriptive language such as text or a markup language (e.g., HTML, SGML and XML). In a preferred embodiment, the markup language is eXtensible Access Control Markup Language (XACML) that is essentially an XML specification for expressing policies for information access. In general, XACML can address fine-grained control of authorized activities, the effect of characteristics of the access requestor, the protocol over which the request is made, authorization based on classes of activities, and content introspection (i.e., authorization based on both the requestor and attribute values within the target where the values of the attributes may not be known to the policy writer). In addition, XACML can suggest a policy authorization model to guide implementers of the authorization mechanism.
  • In general, the data portion of a secured item is a document or file encrypted with a cipher (e.g., a symmetric or asymmetric encryption scheme). Encryption is the transformation of data into a form that is impossible to read without appropriate knowledge (e.g., a key). Its purpose is to ensure privacy by keeping information hidden from anyone to whom it is not intended, even those who have access to other encrypted data. Decryption is the reverse of encryption. Encryption and decryption generally require the use of some secret information, referred to as a key. For some encryption mechanisms, the same key is used for both encryption and decryption; for other mechanisms, the keys used for encryption and decryption are different.
  • For the purpose of controlling the access to the document, the key or keys, referred collectively to as a file key, may be the same or different keys for encryption and decryption and are preferably included in the security information contained in, or pointed to by, the header and, once obtained, can be used to decrypt the encrypted document. To ensure that the key is not to be retrieved or accessible by anyone, the key itself is guarded by the access privileges and rules. If a user requesting the document has the proper access privileges that can be granted by the access rules and system policies if there are any, the key will be retrieved to proceed with the decryption of the encrypted document.
  • To ensure that the security information or the header is not readily revealed, at least a portion of the header itself can be encrypted with a cipher. Depending on an exact implementation, the cipher for the header may or may not be identical to the one used for the document. The key (referred to as a user key) to decrypt the encrypted header can, for example, be stored in a local store of a terminal device and activated only when the user associated with it is authenticated. As a result, only an authorized user can access the secured document. In one embodiment, the key is associated with a user's login to a local server or a central server. Appropriate access privileges associated with the user can then be validated if the user has been authenticated or previously registered with the server and properly logged in. Optionally, the two portions (i.e., the header (possibly encrypted) and the encrypted document) can be encrypted again and only decrypted by a user key. In another option, the encrypted portions (either one or all) can be error-checked by an error-checking portion, such as using a cyclical redundancy check to ensure that no errors have been incurred to the encrypted portion(s) of the secured document.
  • The security system according to the invention can, in general, include or make use of one to many user computers and at least one central server. The security system can also include or make use of one or more local servers as desired. In other words, the security systems operate in a distributed fashion.
  • Referring now to FIG. 3B, there is shown a functional block diagram of a server device 320 in accordance with one embodiment of the invention. The server device includes a server module 322 that resides in a memory space 323 and is executable by one or more processors 321. The server device 320 also includes a network interface 324 to facilitate the communication between the server 320 and other devices on a network, and a local storage space 325. The server module 322 is an executable version of one embodiment of the present invention and delivers, when executed, features/results contemplated in the present invention. According to one embodiment, the server module 322 comprises an administration interface 326, an account manager 328, a system parameter manager 330, a user monitor 332, a local server manager 334, a partner access manager 336, an access report manager 338, and a rules manager 339.
  • Administration Interface 326:
  • As the name suggests, the administration interface 326 facilitates a system administrator to register users and grant respective access privileges to the users and is an entry point to the server module from which all sub-modules or the results thereof can be initiated, updated and managed. In one embodiment, the system administrator sets up hierarchy access levels for various active folders, storage locations, users or group of users. The privileges may include, but not be limited to: open, read, write, print, copy, download and others Examples of the other privileges are altering access privileges for other users, accessing secured documents from one or more locations, and setting up a set of access rules for a folder different from those previously set up (perhaps by the system administrator). The respective user IDs assigned to the users facilitate the management of all the users. Unless specifically stated differently, a user or a corresponding user ID is interchangeably used herein to identify a human user, a software agent, or a group of users and/or software agents. Besides a human user who needs to access a secured document, a software application or agent sometimes needs to access the secured document in order to proceed forward. Accordingly, unless specifically stated, the “user” as used herein does not necessarily pertain to a human being. In general, a user that will access a secured document is associated with a user key to allow an encrypted header in a secured document to be unlocked (decrypted). The expiration or regeneration of a user key may be initiated by the system administrator. According to one embodiment, the administration interface 326 is a user graphic interface showing options for various tasks that an authenticated system administrator or operator may need to perform.
  • Account Manager 328:
  • Essentially, the account manager is a database or an interface to a database 327 (e.g., an Oracle database) maintaining all the registered users and their respective access privileges, and perhaps corresponding user keys (e.g., private and public keys). In operation, the account manager 328 authenticates a user when the user logs onto the server 320 and also determines if the user can access secured documents from the location the user's current location.
  • System Parameters Manager 330:
  • This module is configured to manage system parameters within the server module 322. These system parameters include, for example, user access privileges, system rules, and one or more keys. The system parameters manager 330 can be used to add, delete or modify any of the system parameters. The system parameters manager 330 can also interact with local modules and client modules to supply the system parameters to these distributed modules. For example, a user key can be expired (deleted) for security reasons when a user leaves the organization or when its time to replace the user key. As another example, a file key may be rotated on a periodic or on-demand basis. The system parameters can be supplied to local modules and client modules by a “push” of system parameters to the other distributed modules or by a response to a “pull” request for updated system parameters. Optionally, the system parameters manager 330 may be further configured to act as a key manager managing all keys used in the security system.
  • User Monitor 332:
  • This module is configured to monitor user's requests and whereabouts. Typically, a user is granted to access secured documents from one or more designated locations or networked computers. If a user has a higher access privilege (e.g., to permit access from other than the locations or networked computers), the user monitor 332 may be configured to ensure that the user can have only one access from one of the registered locations or computers at all times. In addition, the user monitor 332 may be configured and scheduled to interact with the system parameters manager 330 to “push” an update of system parameters or respond to a “pull” request for an update of system parameters.
  • Local Server Manager 334:
  • This module is designed to be responsible for distributing an appropriate local module for a local server servicing a predetermined location or a predetermined group of users. According to one embodiment, the local server manager 334 replicates some or all of the server module 322 being executed on the server 320 and distributes the replicated copy to all the local servers. As a result, a user can access secured documents anywhere within the network premises covered by the local servers without being authenticated at a single central server, namely the server 320. According to another embodiment, the local server manager 334 replicates some of the server module 322 being executed on the server 320 and distributes the replicated copy to a corresponding local server, in this embodiment, each of the local servers will have its own customized replication from the server module 322.
  • Partners Access Manager 336:
  • A special module to manage non-employees accounts. The non-employees may be consultants to a business that requires the consultants to access certain secured documents. The partners access manager 336 generally works in accordance with other modules in the server but puts additional restrictions on such users being directly managed by the partners access manager 336. In one application, the partners access manager 336 generates a request to the user key manager 330 to expire a key or key pair for a consultant when an engagement with the consultant ends.
  • Access Report Manager 338:
  • A module is configured to record or track possible access activities and primarily works with a corresponding sub-module in a client module being executed in a client machine. The access report manager 338 is preferably activated by the system administrator and the contents gathered in the access report manager 338 and is typically only accessible by the system administrator.
  • Rules Manager 339:
  • In general, the rules manager 339 is an enforcement mechanism of various access rules. According to one aspect, the rules manager 339 is configured to specify rules based on i) data types (e.g., Microsoft Word), ii) group users or individual, iii) applicable rights, and iv) duration of access rules. Typically, a set of rules is a policy (namely, a security policy). A policy can be enabled, disabled, edited, deployed and undone (e.g., one or two levels). Policies managed by the rules manager 339 operate preferably on a global level. The rules (as well as other system parameters) are typically downloaded to the client machine during the login process (after the user is authenticated) and can be updated dynamically. In addition, respective policies may be associated with active folders (i.e., those designated places to store secured documents). These polices are also downloaded and updated on the client machine. Simple policies can also be embedded in the document and provide document specific policies.
  • According to one embodiment, a header is received by a local server from a client and the access rules from the header are retrieved. The key manager 330 can be called upon to decrypt the encrypted security information in the header. The rules manager 339 can then parse the access rules from the security information and evaluate or measure the access rules against the access privileges of the user to determine whether the secured document can be accessed by the user. If the evaluation or measurement succeeds, a file key is retrieved and sent back to the client.
  • It should be pointed out that the server module 322 in FIG. 3B lists some exemplary modules according to one embodiment of the present invention and not every module in the server module 322 has to be implemented in order to practice the present invention. Those skilled in the art can understand that given the description herein, various combinations of the modules as well as modifications thereof without departing the spirits of the present invention, may achieve various desired functions, benefits and advantages contemplated in the present invention.
  • FIG. 3C shows a functional block diagram of a local server device 340 according to one embodiment of the invention. The local server device 340 executes a module, referred herein as a local module 342 which is configured to be a complete or partial replication of the server module 322 of FIG. 3B. The local server device 340 is generally similar to that of a server as illustrated in FIG. 3B. Namely, the local server device 340 includes one or more processors 341, a memory space 343, a network interface 344, and a local storage space 345. Given the similarity, many parts illustrated in FIG. 3C are not to be described again to avoid obscuring aspects of the present invention. The local module 342 provides the dependability, reliability and scalability of the centralized access control management being undertaken by the central server 320 of FIG. 3B. As such, not all authentication requests need to be handled at one central point without losing control of the access control management. The users are thus not affected if the central server is brought down for maintenance and the connection to the central server is not available. If a number of local servers are used and each has a replication of the server module, the reliability of servicing the users is greatly enhanced. As a result, the local users need only to check with the corresponding local server and none of the users would be affected if other local servers are down for whatever reasons or disconnected from the central server.
  • The configuration of a user's access to secured documents is sometimes referred to as a provisioning process. The dynamic provisioning that has been deserted above is believed to provide the necessary security means needed by a large enterprise having employees in several locations without the loss of the centralized access control management at a central server. Further, the use of multiple local servers to support the central server can provide increased dependability, reliability and sociability.
  • Referring now to FIG. 3D, there is shown a functional block diagram of a client machine 360 according to one embodiment of the invention. As used herein, the client machine 360 is a computing device primarily used by a user to access secured documents. The client machine 360 can, for example, be a desktop computer, a mobile device or a laptop computer. According to one embodiment, the client machine 360 includes a processor 361, a client module 362, a memory space 363, a network interface 365 and a local store 367. The client module 362 resides in the memory space 363 and, when executed by the processor 361, delivers features, advantages and benefits contemplated in the present invention. Through the network interface 365, the client machine 360 is capable of communicating over a data network with other computers, such as a server. From the client machine 360, a user can access secured documents located in a repository (store) 366 that may be in the client machine 360, another networked device, or other storage means. According to one embodiment, the client module 362 includes a number of sub-modules including an access report module 364, a user verifying module 370, a key manager 368, a document securing module 371 and an off-line access manager 374.
  • Access Report Module 364:
  • This module is a software agent configured to record access activity and associated with an authenticated user. It reports to an access report module in the central server so that a record may be established as to what secured document has been accessed by which user during what time. In particular, the access report module 364 can be activated to capture access activities of the user when the client machine is not networked. The access activities will be later synchronized with the counterpart in the server to facilitate the access control management for the offline access.
  • Key Manager 368:
  • One of the purposes for the key manager 368 is to ensure that a secured document is still usable when the secured document is being accessed by an application that suddenly crashes. According to one embodiment, after the encrypted header is decrypted, the file key is then copied or a copy thereof is stored (cached) into the key manager 368. The file key is then used to decrypt the encrypted document. A clear document is now available to the application. If the application crashes due to power outage or interfered by another application or OS, the file key in the header could be damaged. If no copy of the file key is available, the secured document may not be usable any more because the encrypted document would not be decrypted without the file key. In this case, the reserved key maintained in the key manager 368 can be used to replace the damaged key and decrypt the encrypted document. After the user saves the file again, the file key is put back into the header. Another purpose for the key manager 368 is to cache a user key or keys of an authenticated user.
  • User Verifying Module 370:
  • This module is responsible for determining if a user accessing a secured document has been authenticated otherwise it will initiate a request for authentication with a local server or a central server. In other words, the user verifying module 370 is always consulted before a permission is granted to the user seeking access to a secured document. According to one embodiment, a user key or keys of an authenticated user are stored (cached) in the key manager 368 once the user is authenticated by the user verifying module 370 via the server. When a secured document is accessed, the user key must be retrieved from the key manager 368 to decrypt the encrypted security information in the header of the secured document.
  • Document Securing Module 371:
  • As described above, the DSM 371 includes a cipher 372 that is used to generate a file/user key and encrypt/decrypt a document/header. In addition, other securing means may be implemented in the DSM 371, for example, a filter to block copying contents in a secured document into a non-secured document or a link from a secured document/original source to another document or recipient source.
  • Off-Line Access Manager 374:
  • This module becomes effective only when the networked client machine is off the network, namely, the communication with a local server or a central server is not currently available. For example, a user is on the road and still needs to access some secured documents in a laptop computer. When five consultation is not available, the off-line access manager 374 is activated to ensure that the authorized user still can access the secured document but only for a limited time and perhaps with a limited privilege.
  • It should be pointed out that the client module 362 in FIG. 3D lists some exemplary sub-modules according to one embodiment of the present invention and not every module in the server module 362 has to be implemented in order to practice the present invention. Those skilled in the art can understand that given the description herein, various combinations of the sub-modules, may achieve certain functions, benefits and advantages contemplated in the present invention.
  • According to one aspect of the invention, keys that are used to secure files can use arbitrary strings. Such keys are preferably public keys (also known as identity based public keys) that are used to encrypt files (or documents). Specifically, the public keys are arbitrary strings that embed or encode access restrictions (or access rules). The access restrictions are used to enforce access control policies. Counterpart private keys are used to decrypt the files that have been previously encrypted with the public keys. The private keys can be generated to decrypt the portions of the files that have previously been encrypted with the public keys.
  • Because the public keys are based on arbitrary strings, the public keys and their private key counterparts are able to be generated in a decentralized manner (as well as in a centralized manner). The ability to generate keys in a decentralized manner substantially eliminates key distribution burdens and facilitates off-line access to encrypted files. In the embodiments discussed below, the public keys which are based on arbitrary strings are preferably used as file keys to secure files. Often, the file keys are symmetric keys. However, in other embodiments, arbitrary strings can be used with other public keys besides file keys. Such other public keys might, for example, be associated with user keys (also known as a group key when the key pertains to a group of users), clearance keys, or protection keys.
  • FIG. 4 is a block diagram of a file security system 400 according to one embodiment of the invention. The file security system 400 includes an access server 402 and client machines 404 and 406. The access server 402 can pertain to a local server or a central server as noted above with respect to FIGS. 1A-1C. The access server 402 couples to a network 408, and the client machines 404 and 406 also couple to the network 408. The network 408, for example, can pertain to one or more of the Internet, a wide area network, a local area network, etc.
  • The access server 402 includes an access manager 410 and a key generator 412 with a rules engine. The access manager 410 provides centralized control for management of user access to secured files. The secured files can be associated with the access server, such as stored in a file store 414, or associated with client machines 404 and 406 and stored in file stores such as a file store 416 or a file store 418. The access manager 410 communicates with the key generator 412 to decide whether a particular user is granted access to a secure file. In this regard, the key generator 412 within the rules engine evaluates the rules (e.g., access rules) that are associated with the secure file to be accessed. If the rules engine 412 determines that the access requested is permissible, then the key generator 412 generates a key that can be utilized in gaining access to the secure file. The generated key is supplied to the access manager 410. The access manager 410 can either gain access to the secured file using the generated key or can supply the generated key to the appropriate client machine which in turn gains access to the secured file using the generated key. In one embodiment, the generated key can be referred to as a file key.
  • FIG. 5 is a block diagram of a distributed file security system 500 according to one embodiment of the invention. The distributed file security system 500 distributes security operations to local client machines to distribute processing load as well as to reduce key transfer and distribution across networks.
  • The distributed file security system 500 includes an access server 502 and a representative client machine 504 coupled through a network 506. The access server 502 includes at least an access manager 508 that controls access to secure files managed by the distributed file security system 500. The client machine 504 couples to a file store 510 where secured files are stored. In addition, the client machine 504 couples to a hardware (HW) card 512 (e.g., a smart card). The hardware card 512 is, more generally, a peripheral device coupled to the client machine 504. As illustrated in FIG. 5, the hardware card 512 includes an access controller 514, a key generator with rules engine 516 and a key store 518.
  • When a user of the client machine 504 desires to access a secured file that is managed by the distributed file security system 500, the user of the client machine 504 is typically first authenticated by the access manager 508 of the access server 502. Then, a rules string associated with access rules is used as a key (namely, public key) to access the secured file. The key generator with rules engine 516 within the hardware card 512 receives the rule string and evaluates whether the user has sufficient privileges to access the secured file in view of the rules embedded within the rules string. When the key generator with rules engine 516 determines that the user is permitted access to the secured file, the access controller 514 produces a private key which is used to decrypt the secured file. The private key can also be stored to the key store 518. In this embodiment, the private key preferably resides within the hardware card 512 and thus is not transmitted beyond the hardware card 512. In other words, the private key is not stored on the client machine 504, nor does the client key traverse the network 806 to be stored in the access server 502.
  • FIG. 6 is a flow diagram of access rules based encryption processing 600 according to one embodiment of the invention. The access rules based encryption processing 600 is, for example, performed by the access server 402 illustrated in FIG. 4. The access server 402 can represent a central server or a local server of a security system. The access server 402 can also represent the server device 104, 106 illustrated in FIGS. 1A and 1B. Some or all of the access rules based encryption processing 600 can be performed at the client machines 404, 406 of FIG. 4 or the client machines of FIGS. 1A-1C.
  • The access rules based encryption processing 600 initially obtains 602 access rules to be imposed. Namely, the access rules to be imposed are those access rules that are to be applied in securing a file. Next, a rules string is produced 604 in accordance with the access rules.
  • The rules string can follow a predetermined format to embed the access rules. Although the rules string can vary, one example of a rules string is “9:00 am to 5:00 pm<Dec. 31, 2002” which encodes access rules that indicate that access to the associated secured file is only permitted between 9:00 am and 5:00 pm but only prior to Dec. 31, 2002. Another example is “10:00 am-2:00 pm on machine 10.200.255.213” which encodes access rules that indicate that access to the associated secured file is only permitted between 10:00 am and 2:00 pm from a machine having a specific network address. The rules string can also include an access rule that limits access to the secured file to certain groups of users. For example, a group “human resources” could be used in an access rule to limit access to personnel files to only those users that are deemed in the human resources group. Still another example is “Engineering, 9:00 am and 5:00 pm, Mon-Fri, off-line, MS-Word” which encodes access rules that indicate that access to the associated secured file is only permitted by user of the Engineering group, between 9:00 am to 5:00 pm, Monday through Friday, when off-line and when using MS-Word.
  • Once the rules string has been produced 604, a public key is generated 606 based on the rules string. Here, the securing of the file is simplified in that the public key is derived from the rules string which in turn includes the access rules. In other words, the public key is generated based on the rules string. Consequently, the public key is thus not supplied by a key generator (which would require distribution public/private key pairs). Thereafter, at least a portion of the file is encrypted 608 using the public key. In one embodiment, the portion of the file being encrypted 608 is a data portion of the file. Once the portion of the file is encrypted 608, the access rules based encryption processing 600 is complete and ends.
  • FIG. 7 is a flow diagram of access rules based decryption processing 700 according to one embodiment of the invention. The access rules based decryption processing 700 is performed in order to decrypt a file that has been previously encrypted (i.e., secured file).
  • According to the access rules based decryption processing 700, a public key string associated with the secured file is obtained 702. Next, access rules associated with the public key are identified 704. In one embodiment, the access rules can be embedded in the public key string. The access rules are then evaluated 706. A decision 708 then determines whether the access rules are satisfied. Here, the access rules can be compared against access privileges associated with the requestor that desires access to the secured file. These access rules are not only used to formulate a public key, but also used to determine whether the requestor has sufficient privileges and rights to satisfy the access rules and thus gain access to the secured file.
  • When the decision 708 determines that the access rules are not satisfied, then access to the secured file is denied 710. On the other hand, when the decision 708 determines that the access rules are satisfied, then a private key is generated 712 based on the access rules and a master key. In one embodiment, the private key can be referred to as a file key. After the private key has been generated 712, at least a portion of the secured file is decrypted 714 using the private key. In one embodiment, the portion of the secured file being decrypted 714 is a data portion of the secured file. Following the operation 714, as well as following the operation 710, the access rules based decryption processing 700 is complete and ends.
  • As used herein, a master key is used to generate a private key. Hence, access to the master key must be restricted. In one embodiment, the master key is generated or regenerated based on gathered information. In the context of the present invention, the gathered information which may be considered a seed to generate a master key or the master key may itself be distributed among a central server, one or more local servers, and a local device (e.g., a smart card or simply a local client machine). In other words, generation the master key or acquisition of the master key is shared among different machines, none could act alone to obtain the master key to proceed with the processes described herein. In one embodiment, a segment of the information is stored in the central server, another segment of the information is stored in a local server and a third segment of the information is stored in the local device. Only under the condition that the user is authenticated by the server (the central or local server), can the distributed segments of the information be gathered together to generate the master key or recover the master key. Further, the recovered or generated master key can, for example, also be configured to be valid for a certain period of time or for a fixed number of uses to enhance the security thereof.
  • FIG. 8 is a flow diagram of access rules based encryption processing 800 according to another embodiment of the invention. The access rules based encryption 800 is, for example, performed by a distributed file security system, such as the distributed file security system 500 illustrated in FIG. 5.
  • The access rules based encryption processing 800 initially obtains 802 access rules to be imposed when securing a file. Next, a rule string is produced 804 in accordance with the access rules. As noted above with respect to FIG. 6, the rules string can follow a predetermined format to embed the access rules. A key block of the file to be encrypted (or secured) can then be obtained 806. In one embodiment, a key block is a part of a header of a file format that includes one or more keys that are used to decrypt data within a data portion of the file format.
  • A public key for the key block is generated 808 based on the rule string. Here, the public key is able to be relatively easily generated given that it is based on the rules string. In other words, the public key can be generated without requiring the generation of a private/'key pair and without the need to distribute of such keys. After the public key for the key block has been generated 808, the key block of the file is then encrypted 810 using the public key. The encrypted key block is then returned 812 to the requesting device. The encrypted key block is then able to be affixed to the encrypted data portion of the secured file. For example, the encrypted key block can form part of the security information of the header portion of the secured file. In one embodiment, the data portion was previously encrypted using the one or more keys within the key block.
  • FIG. 9 is a flow diagram of access rules based decryption 900 according to one embodiment of the invention. The access rules based decryption processing 900 is, for example, performed by a combination of an access server and a hardware card associated with a distributed data security system.
  • The access rules based decryption processing 900 initially obtains 902 a public key string associated with a secured file. Then, access rules associated with the public key are identified 904. An encrypted key block is also obtained 906. After the access rules have been identified 904, the access rules within the public key are evaluated 908. A decision 910 determines whether the access rules are satisfied. When the decision 910 determines that the access rules are satisfied, then a private key is generated 912 based on the access rules and a master key. Then, the encrypted key block is decrypted 914 to acquire a file key. Thereafter, the file key is utilized to decrypt 916 at least a portion of the secured file using the file key. In one embodiment, the at least the portion of the secured file pertains to a data portion of the secured file.
  • On the other hand, when the decision 910 determines that the access rules are not satisfied, then access to the secured file is denied 918. Additionally, after access to the secured file has been denied 918, additional processing can be performed to restrict unauthorized users from making additional requests to access secured files. For example, a decision 920 can determine whether to “lock down” the file security system to prevent further access to storage resources that store important security keys. When the decision 920 determines that a lock down should be performed, then subsequent access to the secured file, and perhaps other secured files maintained or managed by the same hardware card, are prevented 922. In other words, once the secured file, or the hardware card storing the secured filed, is locked down, the secured file is not able to be being subsequently accessed 922. Following the operations 916 and 922, as well as following the decision 920 when a lock down should not be performed, the access rules based decryption processing 900 is complete and ends.
  • In one embodiment, the operations 908 through 914 are performed internal to a tamper proof device, such as a hardware card (e.g., the hardware card 512 of FIG. 5). As a result, the master key and a key generation algorithm can be stored in the hardware card in a secure manner. The private key being generated can also remain internal to the hardware card. In another embodiment, the master key can have one part (or segment) within the tamper proof device and another part (or segment) on a server or client machine. In such an embodiment, a secure communication cannel can be used for communications between the various devices.
  • The results of the access rules based decryption 700, 900 can be considered a clear file (i.e., decrypted file or decrypted data portion). The clear file refers to the fact that the previously secured file is no longer secured, and is thus usable. The clear file can be returned to the requestor. Nevertheless, the processing described above with respect to the access rules based decryption processing 700, 900 shown in FIGS. 7 and 9 is typically preceded by authorization processing. Authorization processing operates to authenticate the user seeking access to a secured file.
  • FIG. 10 illustrates flow diagrams of an authorization process 1000 according to one embodiment of the invention. The authorization process 1000 begins with a decision 1002 that determines whether a request to access a secured file has been received. When the decision 1002 determines that such a request has not yet been received, the authorization process 1000 waits for such a request. In other words, the authorization process 1000 can be considered to be invoked when a request to access a secured file is received.
  • Once the decision 1002 determines that a request to access a secured file has been received, a decision 1004 determines whether the user and/or the client machine have been authenticated. Typically, the request is initiated by a user of a client machine. For security, both the user and the client machine are authenticated. When the decision 1004 determines that both the user and the client machine have not yet been authenticated, then authentication processing is performed 1006. The authentication processing that is performed 1006 serves to not only authenticate that the user is who the user claims he or she is, but also to determine that the client machine that the user is utilizing is one authorized to be used by the user. In the event that authentication were to be unsuccessful, the authorization process 1000 would end and the user would be unable to access the secured file. Additional details on authentication processing are provided below with reference to FIG. 11.
  • On the other hand, when the decision 1002 determines that the user and the client machine have already been authenticated, as well as after the authentication processing has been performed 1006, a user key associated with the user is retrieved 1008. The user key can be retrieved 1008 from a storage location that is local or remote with respect to the computing device performing the authorization process 1000. After the user key has been retrieved 1008, part or all of the security information in the header portion of the secured file can be decrypted 1010 using the user key. As noted above, the secured file includes a header and a data portion. The header can include, among other things, security information. One component of the security information for the secured file is a file key. The file key can be used to decrypt the data portion of the secured file. Hence, after the security information in the header is decrypted 1010 using the user key, the authorization processing 1000 is complete and ends.
  • FIG. 11 shows a flowchart of a user authentication process 1100 that may be implemented in a server, such as an access server, a central server or a local server. As described above, there are at least two situations that will call upon the user authentication process 1100—initial login to a networked client machine and first access to a secured document. When either of these situations happens, a client module in the client machine initiates a request that is transmitted to a server running a module providing the access control management to start the user authentication process 1100.
  • At a decision 1102, the server awaits a request (e.g., authentication request) from the client machine. Upon receiving the request from the client machine, the server proceeds at a decision 1104 to determine if the user and the client machine from which the user attempts to access a secured document have already been authenticated. If both have already been authenticated, processing skips to operation 1112. On the other hand, the authentication processing 1100 continues when the decision 1104 determines that the user and the client machine have not already been authenticated. In one embodiment, the server may initiate a secured link with the client machine if both the server and the client machine are coupled to an open network, such link may be over HTTPS or supported through VPN. Alternatively, there may be a direct link between the client and the server if another authentication means is employed.
  • Next, the server responds 1106 to the received request with an authentication response. Depending on implementation, such response may be a dialog box to be displayed on the screen of the client machine, a command or other demand. In any case, the response requires that credential information be provided by the user. As described before, the credential information may be a set of username and password or biometric information of the user and must be received from the user. A decision 1108 then causes the authentication processing 1100 to await for such credential information before the authentication processing 1100 may proceed. Upon receiving the credential information, a decision 1110 determines whether the user is authenticated. Here, the decision 1110 can determines whether the user is authenticated to access any secured files. If the decision 1110 determine that the user is not authenticated, the authentication processing 1110 goes back to the beginning of the authentication processing 1100 to continue waiting for a request. In other words, the current request to access the secured documents or login to the system is abandoned. If the decision 1110 determines that the user is authenticated, the user is then recognized as being authentic. At the same time, the client machine can undergo a similar authentication by, perhaps, an IP address thereof, or a network card identification therein, or other means that uniquely identifies the client machine.
  • After authentication of both the user and the client machine, the user's access privilege is activated 1112. Depending on implementation, an activation of the user's access privilege may be a downloading of a file containing the access privilege to the client machine, a decryption of a local file containing the access privilege, or simply an activation of the user in a memory space of the server. In any case, at this point, the user's access privilege(s) is readily accessible, thus permitting the user to access the secured documents from the authenticated client machine.
  • As described above, according to one embodiment, the secured document includes two encrypted portions, the header with encrypted security information and the encrypted data portion (i.e., the encrypted document). The two parts in the secured document are encrypted respectively with two different keys, the file key and the user key. Alternatively, the two encrypted portions may be encrypted again with another key (or use the same user key).
  • The invention also facilitates sharing secured files between different organizations. Here, in one embodiment, a unique company identifier can be encoded into the rules string and thus become part of the public key of the company. Upon receiving a secured file, a user key (a private key) of the company can be generated locally to access the secured file.
  • In the case that there are a number of sets of access rules, each for a particular user or a group of users, it can be understood that the encrypted access rules can be integrated with other sets of the encrypted access rules in a rules block as illustrated in FIG. 3A. As such, access from one user or group will not affect other users or groups but the other users or groups will see perhaps an updated version of the encrypted document.
  • The invention is preferably implemented by software or a combination of hardware and software, but can also be implemented in hardware. The invention can also be embodied as computer readable code on a computer readable medium. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, DVDs, magnetic tape, optical data storage devices, and carrier waves. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.
  • The various embodiments, implementations and features of the invention noted above can be combined in various ways or used separately. Those skilled in the art will understand from the description that the invention can be equally applied to or used in other various different settings with respect to various combinations, embodiments, implementations or features provided in the description herein.
  • The advantages of the invention are numerous. Different embodiments or implementations may yield one or more of the following advantages. One advantage of the invention is that public keys used to encrypt files are not generated prior to protection. Consequently, the system does not need to generate keys in advance and then store and distribute them. Another advantage of the invention is that the public keys encode rules that provide access restrictions. The rules (access rules) are also used to generate the private keys, which protects the rules from being modified. Still another advantage of the invention is that off-line access to protected (secured) documents is facilitated. Yet still another advantage of the invention is that protected files are able to be easily shared between groups within a particular organization as well as between disparate organizations.
  • The foregoing description of embodiments is illustrative of various aspects/embodiments of the present invention. Various modifications to the present invention can be made to the preferred embodiments by those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description of embodiments.

Claims (2)

1. A method for encrypting a file, said method comprising:
obtaining access rules to be imposed;
producing a rules string in accordance with the access rules;
generating a public key based on the rules string; and
encrypting at least a portion of the file using the public key.
2-27. (canceled)
US13/213,172 2001-12-12 2011-08-19 Security system for generating keys from access rules in a decentralized manner and methods therefor Abandoned US20110307937A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US13/213,172 US20110307937A1 (en) 2001-12-12 2011-08-19 Security system for generating keys from access rules in a decentralized manner and methods therefor

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US33963401P 2001-12-12 2001-12-12
US10/075,194 US8065713B1 (en) 2001-12-12 2002-02-12 System and method for providing multi-location access management to secured items
US10/246,079 US8006280B1 (en) 2001-12-12 2002-09-17 Security system for generating keys from access rules in a decentralized manner and methods therefor
US13/213,172 US20110307937A1 (en) 2001-12-12 2011-08-19 Security system for generating keys from access rules in a decentralized manner and methods therefor

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US10/246,079 Continuation US8006280B1 (en) 2001-12-12 2002-09-17 Security system for generating keys from access rules in a decentralized manner and methods therefor

Publications (1)

Publication Number Publication Date
US20110307937A1 true US20110307937A1 (en) 2011-12-15

Family

ID=44455544

Family Applications (2)

Application Number Title Priority Date Filing Date
US10/246,079 Active 2024-10-20 US8006280B1 (en) 2001-12-12 2002-09-17 Security system for generating keys from access rules in a decentralized manner and methods therefor
US13/213,172 Abandoned US20110307937A1 (en) 2001-12-12 2011-08-19 Security system for generating keys from access rules in a decentralized manner and methods therefor

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US10/246,079 Active 2024-10-20 US8006280B1 (en) 2001-12-12 2002-09-17 Security system for generating keys from access rules in a decentralized manner and methods therefor

Country Status (1)

Country Link
US (2) US8006280B1 (en)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8327138B2 (en) 2003-09-30 2012-12-04 Guardian Data Storage Llc Method and system for securing digital assets using process-driven security policies
US8341406B2 (en) 2001-12-12 2012-12-25 Guardian Data Storage, Llc System and method for providing different levels of key security for controlling access to secured items
US8341407B2 (en) 2001-12-12 2012-12-25 Guardian Data Storage, Llc Method and system for protecting electronic data in enterprise environment
US8543827B2 (en) 2001-12-12 2013-09-24 Intellectual Ventures I Llc Methods and systems for providing access control to secured data
US8918839B2 (en) 2001-12-12 2014-12-23 Intellectual Ventures I Llc System and method for providing multi-location access management to secured items
US8964990B1 (en) * 2012-05-17 2015-02-24 Amazon Technologies, Inc. Automating key rotation in a distributed system
US9276754B1 (en) 2012-05-17 2016-03-01 Amazon Technologies, Inc. Key rotation with external workflows
US20160241397A1 (en) * 2015-02-13 2016-08-18 International Business Machines Corporation Automatic Key Management Using Enterprise User Identity Management
CN106209807A (en) * 2016-07-04 2016-12-07 浪潮集团有限公司 A kind of cloud computing safety access control method based on domestic cryptographic algorithm
US20170132427A1 (en) * 2015-11-06 2017-05-11 Océ Printing Systems GmbH & Co. KG Computer system and method to control access to encrypted files
US10033700B2 (en) 2001-12-12 2018-07-24 Intellectual Ventures I Llc Dynamic evaluation of access rights
US10348727B2 (en) 2015-02-13 2019-07-09 International Business Machines Corporation Automatic key management using enterprise user identity management
US10360545B2 (en) 2001-12-12 2019-07-23 Guardian Data Storage, Llc Method and apparatus for accessing secured electronic data off-line
US10979218B2 (en) 2019-03-13 2021-04-13 International Business Machines Corporation Secret generation and share distribution
US11240291B2 (en) * 2015-06-16 2022-02-01 Airwatch Llc Content snip capture and sharing
US11593494B2 (en) 2020-06-03 2023-02-28 Bank Of America Corporation System for monitoring networked computing devices with integrated electronic data encryption and decryption mechanism

Families Citing this family (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10181953B1 (en) * 2013-09-16 2019-01-15 Amazon Technologies, Inc. Trusted data verification
US7565683B1 (en) 2001-12-12 2009-07-21 Weiqing Huang Method and system for implementing changes to security policies in a distributed security system
US8176334B2 (en) * 2002-09-30 2012-05-08 Guardian Data Storage, Llc Document security system that permits external users to gain access to secured files
US8613102B2 (en) 2004-03-30 2013-12-17 Intellectual Ventures I Llc Method and system for providing document retention using cryptography
US7930757B2 (en) * 2003-10-31 2011-04-19 Adobe Systems Incorporated Offline access in a document control system
US8627489B2 (en) 2003-10-31 2014-01-07 Adobe Systems Incorporated Distributed document version control
WO2006107777A2 (en) * 2005-04-01 2006-10-12 Mastercard International Incorporated Dynamic encryption of payment card numbers in electronic payment transactions
US7634584B2 (en) 2005-04-27 2009-12-15 Solarflare Communications, Inc. Packet validation in virtual network interface architecture
US8832047B2 (en) 2005-07-27 2014-09-09 Adobe Systems Incorporated Distributed document version control
US8150038B2 (en) * 2007-11-01 2012-04-03 Oracle America, Inc. Revocation of a system administrator in an encrypted file system
US20130061035A1 (en) * 2010-03-09 2013-03-07 Lock Box Pty Ltd Method and system for sharing encrypted content
US9330245B2 (en) * 2011-12-01 2016-05-03 Dashlane SAS Cloud-based data backup and sync with secure local storage of access keys
US9792451B2 (en) * 2011-12-09 2017-10-17 Echarge2 Corporation System and methods for using cipher objects to protect data
US8990907B2 (en) * 2012-11-09 2015-03-24 Microsoft Corporation Managing security credentials for scaled-out services
US9426124B2 (en) 2013-04-08 2016-08-23 Solarflare Communications, Inc. Locked down network interface
US10742604B2 (en) 2013-04-08 2020-08-11 Xilinx, Inc. Locked down network interface
US20140359789A1 (en) * 2013-05-30 2014-12-04 Telecommunication Systems, Inc. Trusted Circle Information Access Management User Interface
US10515231B2 (en) * 2013-11-08 2019-12-24 Symcor Inc. Method of obfuscating relationships between data in database tables
US9503461B2 (en) * 2014-12-30 2016-11-22 International Business Machines Corporation Authentication based on proximate devices
US10049228B2 (en) * 2015-01-20 2018-08-14 Microsoft Technology Licensing, Llc File encryption support for FAT file systems
US9807117B2 (en) 2015-03-17 2017-10-31 Solarflare Communications, Inc. System and apparatus for providing network security
US9842062B2 (en) 2015-05-31 2017-12-12 Apple Inc. Backup accessible by subset of related devices
US10079919B2 (en) 2016-05-27 2018-09-18 Solarflare Communications, Inc. Method, apparatus and computer program product for processing data
US10574648B2 (en) 2016-12-22 2020-02-25 Dashlane SAS Methods and systems for user authentication
US10432397B2 (en) 2017-05-03 2019-10-01 Dashlane SAS Master password reset in a zero-knowledge architecture
US10211979B2 (en) * 2017-05-19 2019-02-19 Swfl, Inc. Systems and methods securing an autonomous device
US10848312B2 (en) 2017-11-14 2020-11-24 Dashlane SAS Zero-knowledge architecture between multiple systems
US10904004B2 (en) 2018-02-27 2021-01-26 Dashlane SAS User-session management in a zero-knowledge environment
US11405401B2 (en) * 2020-05-21 2022-08-02 Adp, Inc. Determining and applying assurance levels for application operations security

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5745573A (en) * 1994-08-11 1998-04-28 Trusted Information Systems, Inc. System and method for controlling access to a user secret
US6085323A (en) * 1996-04-15 2000-07-04 Kabushiki Kaisha Toshiba Information processing system having function of securely protecting confidential information
US6134660A (en) * 1997-06-30 2000-10-17 Telcordia Technologies, Inc. Method for revoking computer backup files using cryptographic techniques
US6292899B1 (en) * 1998-09-23 2001-09-18 Mcbride Randall C. Volatile key apparatus for safeguarding confidential data stored in a computer system memory
US6449721B1 (en) * 1999-05-28 2002-09-10 Authentica Security Technologies, Inc. Method of encrypting information for remote access while maintaining access control
US6647388B2 (en) * 1999-12-16 2003-11-11 International Business Machines Corporation Access control system, access control method, storage medium and program transmission apparatus
US6810389B1 (en) * 2000-11-08 2004-10-26 Synopsys, Inc. System and method for flexible packaging of software application licenses
US6891953B1 (en) * 2000-06-27 2005-05-10 Microsoft Corporation Method and system for binding enhanced software features to a persona
US7224795B2 (en) * 1999-10-20 2007-05-29 Fujitsu Limited Variable-length key cryptosystem

Family Cites Families (563)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4238854A (en) 1977-12-05 1980-12-09 International Business Machines Corporation Cryptographic file security for single domain networks
US4203166A (en) 1977-12-05 1980-05-13 International Business Machines Corporation Cryptographic file security for multiple domain networks
NL8001492A (en) 1980-03-13 1981-10-01 Philips Nv POWER MIRROR SWITCH.
US4799258A (en) 1984-02-13 1989-01-17 National Research Development Corporation Apparatus and methods for granting access to computers
US4972472A (en) 1985-03-15 1990-11-20 Tandem Computers Incorporated Method and apparatus for changing the master key in a cryptographic system
JPH0818473B2 (en) 1985-07-31 1996-02-28 トッパン・ムーア株式会社 IC card that can set confidentiality level
US4757533A (en) 1985-09-11 1988-07-12 Computer Security Corporation Security system for microcomputers
US4827508A (en) 1986-10-14 1989-05-02 Personal Library Software, Inc. Database usage metering and protection system and method
US4796220A (en) 1986-12-15 1989-01-03 Pride Software Development Corp. Method of controlling the copying of software
US4887204A (en) 1987-02-13 1989-12-12 International Business Machines Corporation System and method for accessing remote files in a distributed networking environment
GB8704920D0 (en) 1987-03-03 1987-04-08 Hewlett Packard Co Secure messaging system
US5220657A (en) 1987-12-02 1993-06-15 Xerox Corporation Updating local copy of shared data in a collaborative system
US4912552A (en) 1988-04-19 1990-03-27 Control Data Corporation Distributed monitoring system
US5247575A (en) 1988-08-16 1993-09-21 Sprague Peter J Information distribution system
US5144660A (en) 1988-08-31 1992-09-01 Rose Anthony M Securing a computer against undesired write operations to or read operations from a mass storage device
JP3143108B2 (en) 1990-03-13 2001-03-07 株式会社日立製作所 File encryption method and file encryption system
US5058164A (en) 1990-05-03 1991-10-15 National Semiconductor Corp. Encryption of streams of addressed information to be used for program code protection
US5212788A (en) 1990-05-22 1993-05-18 Digital Equipment Corporation System and method for consistent timestamping in distributed computer databases
US5052040A (en) 1990-05-25 1991-09-24 Micronyx, Inc. Multiple user stored data cryptographic labeling system and method
US5032979A (en) 1990-06-22 1991-07-16 International Business Machines Corporation Distributed security auditing subsystem for an operating system
US5204897A (en) 1991-06-28 1993-04-20 Digital Equipment Corporation Management interface for license management system
PT100905A (en) 1991-09-30 1994-02-28 Eisai Co Ltd BICYCLE HYGIENEOUS HETEROCYCLIC COMPOUNDS CONTAINING BENZENE, CYCLOHEXAN OR PYRIDINE AND PYRIMIDINE, PYRIDINE OR IMIDAZOLE SUBSTITUTES AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM
US5461710A (en) 1992-03-20 1995-10-24 International Business Machines Corporation Method for providing a readily distinguishable template and means of duplication thereof in a computer system graphical user interface
US5276735A (en) 1992-04-17 1994-01-04 Secure Computing Corporation Data enclave and trusted path system
JPH0619771A (en) 1992-04-20 1994-01-28 Internatl Business Mach Corp <Ibm> File management system of shared file by different kinds of clients
US6608636B1 (en) 1992-05-13 2003-08-19 Ncr Corporation Server based virtual conferencing
US5301247A (en) 1992-07-23 1994-04-05 Crest Industries, Inc. Method for ensuring secure communications
US5319705A (en) 1992-10-21 1994-06-07 International Business Machines Corporation Method and system for multimedia access control enablement
US5414852A (en) 1992-10-30 1995-05-09 International Business Machines Corporation Method for protecting data in a computer system
JP2800603B2 (en) 1992-12-01 1998-09-21 三菱電機株式会社 Information processing device using icons
WO1994014119A1 (en) 1992-12-07 1994-06-23 Raxco, Incorporated Apparatus and method for moving open files
US5299263A (en) 1993-03-04 1994-03-29 Bell Communications Research, Inc. Two-way public key authentication and key agreement for low-cost terminals
US5638501A (en) 1993-05-10 1997-06-10 Apple Computer, Inc. Method and apparatus for displaying an overlay image
US5375169A (en) 1993-05-28 1994-12-20 Tecsec, Incorporated Cryptographic key management method and apparatus
US5404404A (en) 1993-07-01 1995-04-04 Motorola, Inc. Method for updating encryption key information in communication units
AU7620394A (en) 1993-09-14 1995-04-03 Chantilley Corporation Limited Apparatus for key distribution in an encryption system
US5677953A (en) 1993-09-14 1997-10-14 Spyrus, Inc. System and method for access control for portable data storage media
JP2828218B2 (en) 1993-09-20 1998-11-25 インターナシヨナル・ビジネス・マシーンズ・コーポレーシヨン Method and system for changing an authorized password or key in a distributed communication network
JP3717176B2 (en) 1993-09-29 2005-11-16 株式会社パンプキンハウス Encryption / decryption device and method
US5497422A (en) 1993-09-30 1996-03-05 Apple Computer, Inc. Message protection mechanism and graphical user interface therefor
JP3263878B2 (en) 1993-10-06 2002-03-11 日本電信電話株式会社 Cryptographic communication system
US5369702A (en) 1993-10-18 1994-11-29 Tecsec Incorporated Distributed cryptographic object method
US5680452A (en) 1993-10-18 1997-10-21 Tecsec Inc. Distributed cryptographic object method
US5689688A (en) 1993-11-16 1997-11-18 International Business Machines Corporation Probabilistic anonymous clock synchronization method and apparatus for synchronizing a local time scale with a reference time scale
US5999907A (en) 1993-12-06 1999-12-07 Donner; Irah H. Intellectual property audit system
US5434918A (en) 1993-12-14 1995-07-18 Hughes Aircraft Company Method for providing mutual authentication of a user and a server on a network
JP2596361B2 (en) 1993-12-24 1997-04-02 日本電気株式会社 Password update method
JP3501485B2 (en) 1993-12-24 2004-03-02 キヤノン株式会社 Multimedia device management system and management method
US5584023A (en) 1993-12-27 1996-12-10 Hsu; Mike S. C. Computer system including a transparent and secure file transform mechanism
US5467342A (en) 1994-01-12 1995-11-14 Scientific-Atlanta, Inc. Methods and apparatus for time stamp correction in an asynchronous transfer mode network
EP1265122A3 (en) 1994-03-15 2006-01-18 Kabushiki Kaisha Toshiba Shared file editing system with file content secrecy, version management and asynchronous editing
US5499298A (en) 1994-03-17 1996-03-12 National University Of Singapore Controlled dissemination of digital information
FR2718312B1 (en) 1994-03-29 1996-06-07 Rola Nevoux Method for the combined authentication of a telecommunications terminal and a user module.
US5495533A (en) 1994-04-29 1996-02-27 International Business Machines Corporation Personal key archive
US5528516A (en) 1994-05-25 1996-06-18 System Management Arts, Inc. Apparatus and method for event correlation and problem reporting
US7107185B1 (en) 1994-05-25 2006-09-12 Emc Corporation Apparatus and method for event correlation and problem reporting
US5499040A (en) 1994-06-27 1996-03-12 Radius Inc. Method and apparatus for display calibration and control
US5720033A (en) 1994-06-30 1998-02-17 Lucent Technologies Inc. Security platform and method using object oriented rules for computer-based systems using UNIX-line operating systems
US5999711A (en) 1994-07-18 1999-12-07 Microsoft Corporation Method and system for providing certificates holding authentication and authorization information for users/machines
US5881287A (en) 1994-08-12 1999-03-09 Mast; Michael B. Method and apparatus for copy protection of images in a computer system
US5944794A (en) 1994-09-30 1999-08-31 Kabushiki Kaisha Toshiba User identification data management scheme for networking computer systems using wide area network
US5715403A (en) 1994-11-23 1998-02-03 Xerox Corporation System for controlling the distribution and use of digital works having attached usage rights where the usage rights are defined by a usage rights grammar
US5892900A (en) 1996-08-30 1999-04-06 Intertrust Technologies Corp. Systems and methods for secure transaction management and electronic rights protection
DE69637799D1 (en) 1995-02-13 2009-02-12 Intertrust Tech Corp Systems and procedures for secure transaction management and electronic legal protection
US7133845B1 (en) 1995-02-13 2006-11-07 Intertrust Technologies Corp. System and methods for secure transaction management and electronic rights protection
US6272632B1 (en) 1995-02-21 2001-08-07 Network Associates, Inc. System and method for controlling access to a user secret using a key recovery field
US5600726A (en) * 1995-04-07 1997-02-04 Gemini Systems, L.L.C. Method for creating specific purpose rule-based n-bit virtual machines
US5835592A (en) 1995-06-01 1998-11-10 Chang; Chung Nan Secure, swift cryptographic key exchange
US6011847A (en) 1995-06-01 2000-01-04 Follendore, Iii; Roy D. Cryptographic access and labeling system
AU6252496A (en) 1995-06-07 1996-12-30 E-Systems Incorporated Apparatus and method for centralized storage of heterogeneou s medical records in managed health care organization
US5628005A (en) 1995-06-07 1997-05-06 Microsoft Corporation System and method for providing opportunistic file access in a network environment
US5813009A (en) 1995-07-28 1998-09-22 Univirtual Corp. Computer based records management system method
US5671412A (en) 1995-07-28 1997-09-23 Globetrotter Software, Incorporated License management system for software applications
US5682537A (en) 1995-08-31 1997-10-28 Unisys Corporation Object lock management system with improved local lock management and global deadlock detection in a parallel data processing system
US5821933A (en) 1995-09-14 1998-10-13 International Business Machines Corporation Visual access to restricted functions represented on a graphical user interface
US6807534B1 (en) 1995-10-13 2004-10-19 Trustees Of Dartmouth College System and method for managing copyrighted electronic media
US5765152A (en) 1995-10-13 1998-06-09 Trustees Of Dartmouth College System and method for managing copyrighted electronic media
US5787175A (en) 1995-10-23 1998-07-28 Novell, Inc. Method and apparatus for collaborative document control
US6023506A (en) 1995-10-26 2000-02-08 Hitachi, Ltd. Data encryption control apparatus and method
US5732265A (en) 1995-11-02 1998-03-24 Microsoft Corporation Storage optimizing encoder and method
US5729734A (en) 1995-11-03 1998-03-17 Apple Computer, Inc. File privilege administration apparatus and methods
US5751287A (en) 1995-11-06 1998-05-12 Documagix, Inc. System for organizing document icons with suggestions, folders, drawers, and cabinets
US5689625A (en) 1995-11-28 1997-11-18 Xerox Corporation Document server for processing a distribution job in a document processing system
US5778350A (en) 1995-11-30 1998-07-07 Electronic Data Systems Corporation Data collection, processing, and reporting system
US5825876A (en) 1995-12-04 1998-10-20 Northern Telecom Time based availability to content of a storage medium
US5708709A (en) 1995-12-08 1998-01-13 Sun Microsystems, Inc. System and method for managing try-and-buy usage of application programs
US5745750A (en) 1995-12-15 1998-04-28 International Business Machines Corporation Process and article of manufacture for constructing and optimizing transaction logs for mobile file systems
US5640388A (en) 1995-12-21 1997-06-17 Scientific-Atlanta, Inc. Method and apparatus for removing jitter and correcting timestamps in a packet stream
US5787169A (en) 1995-12-28 1998-07-28 International Business Machines Corp. Method and apparatus for controlling access to encrypted data files in a computer system
JPH09190236A (en) 1996-01-10 1997-07-22 Canon Inc Method, device and system for processing information
EP0880840A4 (en) 1996-01-11 2002-10-23 Mrj Inc System for controlling access and distribution of digital property
US5719941A (en) 1996-01-12 1998-02-17 Microsoft Corporation Method for changing passwords on a remote computer
US5699428A (en) 1996-01-16 1997-12-16 Symantec Corporation System for automatic decryption of file data on a per-use basis and automatic re-encryption within context of multi-threaded operating system under which applications run in real-time
DE69714422T2 (en) 1996-02-09 2002-11-14 Digital Privacy Inc ACCESS CONTROL / ENCRYPTION SYSTEM
US5862325A (en) 1996-02-29 1999-01-19 Intermind Corporation Computer-based communication system and method using metadata defining a control structure
US5870468A (en) 1996-03-01 1999-02-09 International Business Machines Corporation Enhanced data privacy for portable computers
JP3486043B2 (en) 1996-03-11 2004-01-13 株式会社東芝 Operating method of software distribution system and software system
US6038551A (en) * 1996-03-11 2000-03-14 Microsoft Corporation System and method for configuring and managing resources on a multi-purpose integrated circuit card using a personal computer
US6055314A (en) 1996-03-22 2000-04-25 Microsoft Corporation System and method for secure purchase and delivery of video content programs
US5673316A (en) 1996-03-29 1997-09-30 International Business Machines Corporation Creation and distribution of cryptographic envelope
US5970502A (en) 1996-04-23 1999-10-19 Nortel Networks Corporation Method and apparatus for synchronizing multiple copies of a database
US5953419A (en) 1996-05-06 1999-09-14 Symantec Corporation Cryptographic file labeling system for supporting secured access by multiple users
US5857189A (en) 1996-05-08 1999-01-05 Apple Computer, Inc. File sharing in a teleconference application
US6526512B1 (en) 1996-05-20 2003-02-25 Ncr Corporation Access key codes for computer resources
US5748736A (en) 1996-06-14 1998-05-05 Mittra; Suvo System and method for secure group communications via multicast or broadcast
IL128099A (en) 1996-07-22 2004-05-12 Cyva Res Corp Personal information security and exchange tool
US5790789A (en) 1996-08-02 1998-08-04 Suarez; Larry Method and architecture for the creation, control and deployment of services within a distributed computer environment
US5850443A (en) 1996-08-15 1998-12-15 Entrust Technologies, Ltd. Key management system for mixed-trust environments
US5790790A (en) 1996-10-24 1998-08-04 Tumbleweed Software Corporation Electronic document delivery system in which notification of said electronic document is sent to a recipient thereof
US6192407B1 (en) 1996-10-24 2001-02-20 Tumbleweed Communications Corp. Private, trackable URLs for directed document delivery
US6909708B1 (en) 1996-11-18 2005-06-21 Mci Communications Corporation System, method and article of manufacture for a communication system architecture including video conferencing
US7145898B1 (en) 1996-11-18 2006-12-05 Mci Communications Corporation System, method and article of manufacture for selecting a gateway of a hybrid communication system architecture
US6061790A (en) 1996-11-20 2000-05-09 Starfish Software, Inc. Network computer system with remote user data encipher methodology
US7136903B1 (en) 1996-11-22 2006-11-14 Mangosoft Intellectual Property, Inc. Internet-based shared file service with native PC client access and semantics and distributed access control
US7177839B1 (en) 1996-12-13 2007-02-13 Certco, Inc. Reliance manager for electronic transaction system
US6014730A (en) 1996-12-26 2000-01-11 Nec Corporation Dynamic adding system for memory files shared among hosts, dynamic adding method for memory files shared among hosts, and computer-readable medium recording dynamic adding program for memory files shared among hosts
AU6151598A (en) 1997-02-11 1998-08-26 Connected Corporation File comparison for data backup and file synchronization
US6885747B1 (en) 1997-02-13 2005-04-26 Tec.Sec, Inc. Cryptographic key split combiner
US5922074A (en) 1997-02-28 1999-07-13 Xcert Software, Inc. Method of and apparatus for providing secure distributed directory services and public key infrastructure
US6069957A (en) 1997-03-07 2000-05-30 Lucent Technologies Inc. Method and apparatus for providing hierarchical key system in restricted-access television system
US6226745B1 (en) 1997-03-21 2001-05-01 Gio Wiederhold Information sharing system and method with requester dependent sharing and security rules
US5923754A (en) 1997-05-02 1999-07-13 Compaq Computer Corporation Copy protection for recorded media
US20020069077A1 (en) 1997-05-19 2002-06-06 Westport Benefits, L.L.C. Computerized system for customizing and managing benefits
US6381698B1 (en) 1997-05-21 2002-04-30 At&T Corp System and method for providing assurance to a host that a piece of software possesses a particular property
US6134658A (en) 1997-06-09 2000-10-17 Microsoft Corporation Multi-server location-independent authentication certificate management system
US6105131A (en) 1997-06-13 2000-08-15 International Business Machines Corporation Secure server and method of operation for a distributed information system
JPH1115373A (en) 1997-06-20 1999-01-22 Fuji Xerox Co Ltd Open key coding system
US6272631B1 (en) 1997-06-30 2001-08-07 Microsoft Corporation Protected storage of core data secrets
US6032216A (en) 1997-07-11 2000-02-29 International Business Machines Corporation Parallel file system with method using tokens for locking modes
US6603857B1 (en) 1997-07-14 2003-08-05 Entrust Technologies Limited Method and apparatus for controlling release of time sensitive information
US6314408B1 (en) * 1997-07-15 2001-11-06 Eroom Technology, Inc. Method and apparatus for controlling access to a product
US6370249B1 (en) 1997-07-25 2002-04-09 Entrust Technologies, Ltd. Method and apparatus for public key management
US6442688B1 (en) 1997-08-29 2002-08-27 Entrust Technologies Limited Method and apparatus for obtaining status of public key certificate updates
US6035404A (en) 1997-09-09 2000-03-07 International Business Machines Corporation Concurrent user access control in stateless network computing service system
US6405315B1 (en) 1997-09-11 2002-06-11 International Business Machines Corporation Decentralized remotely encrypted file system
GB2329497B (en) 1997-09-19 2001-01-31 Ibm Method for controlling access to electronically provided services and system for implementing such method
WO1999015947A1 (en) 1997-09-19 1999-04-01 Hyo Joon Park Software license control system based on independent software registration server
US6192408B1 (en) 1997-09-26 2001-02-20 Emc Corporation Network file server sharing local caches of file access information in data processors assigned to respective file systems
US6490620B1 (en) 1997-09-26 2002-12-03 Worldcom, Inc. Integrated proxy interface for web based broadband telecommunications management
US6031584A (en) 1997-09-26 2000-02-29 Intel Corporation Method for reducing digital video frame frequency while maintaining temporal smoothness
US6611599B2 (en) 1997-09-29 2003-08-26 Hewlett-Packard Development Company, L.P. Watermarking of digital object
US5968177A (en) 1997-10-14 1999-10-19 Entrust Technologies Limited Method and apparatus for processing administration of a secured community
US6421714B1 (en) 1997-10-14 2002-07-16 Lucent Technologies Efficient mobility management scheme for a wireless internet access system
JP4036406B2 (en) 1997-10-14 2008-01-23 キヤノン株式会社 Data communication apparatus, data communication method, information processing terminal control method, and computer-readable storage medium
US6917962B1 (en) 1997-10-22 2005-07-12 Brokercom Inc. Web-based groupware system
US5991879A (en) 1997-10-23 1999-11-23 Bull Hn Information Systems Inc. Method for gradual deployment of user-access security within a data processing system
US6134327A (en) 1997-10-24 2000-10-17 Entrust Technologies Ltd. Method and apparatus for creating communities of trust in a secure communication system
US6223285B1 (en) 1997-10-24 2001-04-24 Sony Corporation Of Japan Method and system for transferring information using an encryption mode indicator
WO1999023538A1 (en) * 1997-10-28 1999-05-14 Georgia Tech Research Corporation Adaptive data security system and method
US6085191A (en) 1997-10-31 2000-07-04 Sun Microsystems, Inc. System and method for providing database access control in a secure distributed network
US6064656A (en) 1997-10-31 2000-05-16 Sun Microsystems, Inc. Distributed system and method for controlling access control to network resources
US6070244A (en) 1997-11-10 2000-05-30 The Chase Manhattan Bank Computer network security management system
EP1717695A1 (en) 1997-11-14 2006-11-02 Microsoft Corporation Server operating system for supporting multiple client-server sessions and dynamic reconnection of users to previous sessions
US6058424A (en) 1997-11-17 2000-05-02 International Business Machines Corporation System and method for transferring a session from one application server to another without losing existing resources
US6098056A (en) 1997-11-24 2000-08-01 International Business Machines Corporation System and method for controlling access rights to and security of digital content in a distributed information system, e.g., Internet
US6141754A (en) 1997-11-28 2000-10-31 International Business Machines Corporation Integrated method and system for controlling information access and distribution
US6490680B1 (en) 1997-12-04 2002-12-03 Tecsec Incorporated Access control and authorization system
US6202157B1 (en) 1997-12-08 2001-03-13 Entrust Technologies Limited Computer network security system and method having unilateral enforceable security policy provision
US7283561B1 (en) 1997-12-12 2007-10-16 Level 3 Communications, Llc Secure network architecture with quality of service
JPH11191149A (en) 1997-12-26 1999-07-13 Oki Electric Ind Co Ltd Lsi for ic card and using method therefor
US6260040B1 (en) 1998-01-05 2001-07-10 International Business Machines Corporation Shared file system for digital content
JPH11232226A (en) 1998-02-13 1999-08-27 Nec Corp Cooperative work aiding system and storage medium
US6088805A (en) 1998-02-13 2000-07-11 International Business Machines Corporation Systems, methods and computer program products for authenticating client requests with client certificate information
US6357010B1 (en) 1998-02-17 2002-03-12 Secure Computing Corporation System and method for controlling access to documents stored on an internal network
US7233948B1 (en) 1998-03-16 2007-06-19 Intertrust Technologies Corp. Methods and apparatus for persistent control and protection of content
US6453419B1 (en) 1998-03-18 2002-09-17 Secure Computing Corporation System and method for implementing a security policy
JP4169822B2 (en) 1998-03-18 2008-10-22 富士通株式会社 Data protection method for storage medium, apparatus therefor, and storage medium therefor
US6615350B1 (en) 1998-03-23 2003-09-02 Novell, Inc. Module authentication and binding library extensions
US6148338A (en) 1998-04-03 2000-11-14 Hewlett-Packard Company System for logging and enabling ordered retrieval of management events
US6243369B1 (en) 1998-05-06 2001-06-05 Terayon Communication Systems, Inc. Apparatus and method for synchronizing an SCDMA upstream or any other type upstream to an MCNS downstream or any other type downstream with a different clock rate than the upstream
US6711683B1 (en) 1998-05-29 2004-03-23 Texas Instruments Incorporated Compresses video decompression system with encryption of compressed data stored in video buffer
US6347374B1 (en) 1998-06-05 2002-02-12 Intrusion.Com, Inc. Event detection
US6505300B2 (en) 1998-06-12 2003-01-07 Microsoft Corporation Method and system for secure running of untrusted content
US6308273B1 (en) 1998-06-12 2001-10-23 Microsoft Corporation Method and system of security location discrimination
US6298446B1 (en) 1998-06-14 2001-10-02 Alchemedia Ltd. Method and system for copyright protection of digital images transmitted over networks
US6199070B1 (en) 1998-06-18 2001-03-06 International Business Machines Corporation Using a database for program logs
US6263348B1 (en) 1998-07-01 2001-07-17 Serena Software International, Inc. Method and apparatus for identifying the existence of differences between two files
US6336114B1 (en) 1998-09-03 2002-01-01 Westcorp Software Systems, Inc. System and method for restricting access to a data table within a database
US6735701B1 (en) 1998-06-25 2004-05-11 Macarthur Investments, Llc Network policy management and effectiveness system
US6625650B2 (en) 1998-06-27 2003-09-23 Intel Corporation System for multi-layer broadband provisioning in computer networks
US6295361B1 (en) 1998-06-30 2001-09-25 Sun Microsystems, Inc. Method and apparatus for multicast indication of group key change
US6594662B1 (en) 1998-07-01 2003-07-15 Netshadow, Inc. Method and system for gathering information resident on global computer networks
US6134664A (en) 1998-07-06 2000-10-17 Prc Inc. Method and system for reducing the volume of audit data and normalizing the audit data received from heterogeneous sources
US6182142B1 (en) 1998-07-10 2001-01-30 Encommerce, Inc. Distributed access management of information resources
US6453353B1 (en) 1998-07-10 2002-09-17 Entrust, Inc. Role-based navigation of information resources
US6567914B1 (en) 1998-07-22 2003-05-20 Entrust Technologies Limited Apparatus and method for reducing transmission bandwidth and storage requirements in a cryptographic security system
US6341164B1 (en) 1998-07-22 2002-01-22 Entrust Technologies Limited Method and apparatus for correcting improper encryption and/or for reducing memory storage
US6408404B1 (en) 1998-07-29 2002-06-18 Northrop Grumman Corporation System and method for ensuring and managing situation awareness
US6438235B2 (en) 1998-08-05 2002-08-20 Hewlett-Packard Company Media content protection utilizing public key cryptography
US6226618B1 (en) 1998-08-13 2001-05-01 International Business Machines Corporation Electronic content delivery system
US6466932B1 (en) 1998-08-14 2002-10-15 Microsoft Corporation System and method for implementing group policy
US6205549B1 (en) 1998-08-28 2001-03-20 Adobe Systems, Inc. Encapsulation of public key cryptography standard number 7 into a secured document
US6185684B1 (en) 1998-08-28 2001-02-06 Adobe Systems, Inc. Secured document access control using recipient lists
US20020062451A1 (en) * 1998-09-01 2002-05-23 Scheidt Edward M. System and method of providing communication security
KR100484209B1 (en) 1998-09-24 2005-09-30 삼성전자주식회사 Digital Content Encryption / Decryption Device and Method
IL126472A0 (en) 1998-10-07 1999-08-17 Nds Ltd Secure communications system
US6145084A (en) 1998-10-08 2000-11-07 Net I Trust Adaptive communication system enabling dissimilar devices to exchange information over a network
US6266420B1 (en) 1998-10-08 2001-07-24 Entrust Technologies Limited Method and apparatus for secure group communications
US6212561B1 (en) 1998-10-08 2001-04-03 Cisco Technology, Inc. Forced sequential access to specified domains in a computer network
US6038322A (en) 1998-10-20 2000-03-14 Cisco Technology, Inc. Group key distribution
US6519700B1 (en) 1998-10-23 2003-02-11 Contentguard Holdings, Inc. Self-protecting documents
US6158010A (en) 1998-10-28 2000-12-05 Crosslogix, Inc. System and method for maintaining security in a distributed computer network
AU1347100A (en) 1998-11-13 2000-06-05 Chase Manhattan Bank, The A system and method for managing information retrievals from distributed archives
US6530024B1 (en) 1998-11-20 2003-03-04 Centrax Corporation Adaptive feedback security system and method
US6154543A (en) 1998-11-25 2000-11-28 Hush Communications Anguilla, Inc. Public key cryptosystem with roaming user capability
US6442695B1 (en) 1998-12-03 2002-08-27 International Business Machines Corporation Establishment of user home directories in a heterogeneous network environment
US20030172280A1 (en) 1998-12-04 2003-09-11 Scheidt Edward M. Access control and authorization system
US6343280B2 (en) 1998-12-15 2002-01-29 Jonathan Clark Distributed execution software license server
JP2000181803A (en) 1998-12-18 2000-06-30 Fujitsu Ltd Electronic data keeping device with key management function and method therefor
CA2256936C (en) 1998-12-23 2002-04-02 Hamid Bacha System for electronic repository of data enforcing access control on data search and retrieval
US6587946B1 (en) 1998-12-29 2003-07-01 Lucent Technologies Inc. Method and system for quorum controlled asymmetric proxy encryption
US6356903B1 (en) 1998-12-30 2002-03-12 American Management Systems, Inc. Content management system
JP4745478B2 (en) 1999-01-29 2011-08-10 キヤノン株式会社 Network print system, information processing apparatus and control method therefor
FR2789829B1 (en) 1999-02-11 2001-04-20 Bull Sa METHOD FOR VERIFYING THE USE OF PUBLIC KEYS GENERATED BY AN ON-BOARD SYSTEM
JP3779837B2 (en) 1999-02-22 2006-05-31 松下電器産業株式会社 Computer and program recording medium
US6356941B1 (en) 1999-02-22 2002-03-12 Cyber-Ark Software Ltd. Network vaults
US6615349B1 (en) 1999-02-23 2003-09-02 Parsec Sight/Sound, Inc. System and method for manipulating a computer file and/or program
US20020026321A1 (en) 1999-02-26 2002-02-28 Sadeg M. Faris Internet-based system and method for fairly and securely enabling timed-constrained competition using globally time-sychronized client subsystems and information servers having microsecond client-event resolution
US6405318B1 (en) 1999-03-12 2002-06-11 Psionic Software, Inc. Intrusion detection system
US6081900A (en) 1999-03-16 2000-06-27 Novell, Inc. Secure intranet access
US7073063B2 (en) * 1999-03-27 2006-07-04 Microsoft Corporation Binding a digital license to a portable device or the like in a digital rights management (DRM) system and checking out/checking in the digital license to/from the portable device or the like
US6775779B1 (en) 1999-04-06 2004-08-10 Microsoft Corporation Hierarchical trusted code for content protection in computers
US6584466B1 (en) 1999-04-07 2003-06-24 Critical Path, Inc. Internet document management system and methods
US6907034B1 (en) 1999-04-08 2005-06-14 Intel Corporation Out-of-band signaling for network based computer session synchronization
JP4314745B2 (en) 1999-04-16 2009-08-19 ソニー株式会社 Data processing system, data processing method, and data processing apparatus
US6625734B1 (en) 1999-04-26 2003-09-23 Disappearing, Inc. Controlling and tracking access to disseminated information
US6317777B1 (en) 1999-04-26 2001-11-13 Intel Corporation Method for web based storage and retrieval of documents
US6738908B1 (en) 1999-05-06 2004-05-18 Watchguard Technologies, Inc. Generalized network security policy templates for implementing similar network security policies across multiple networks
US6735313B1 (en) 1999-05-07 2004-05-11 Lucent Technologies Inc. Cryptographic method and apparatus for restricting access to transmitted programming content using hash functions and program identifiers
US6282304B1 (en) 1999-05-14 2001-08-28 Biolink Technologies International, Inc. Biometric system for biometric input, comparison, authentication and access control and method therefor
US6801999B1 (en) 1999-05-20 2004-10-05 Microsoft Corporation Passive and active software objects containing bore resistant watermarking
US6775372B1 (en) 1999-06-02 2004-08-10 Dictaphone Corporation System and method for multi-stage data logging
US6393420B1 (en) 1999-06-03 2002-05-21 International Business Machines Corporation Securing Web server source documents and executables
US6122630A (en) 1999-06-08 2000-09-19 Iti, Inc. Bidirectional database replication scheme for controlling ping-ponging
US6959384B1 (en) 1999-12-14 2005-10-25 Intertrust Technologies Corporation Systems and methods for authenticating and protecting the integrity of data streams and other data
US6785815B1 (en) 1999-06-08 2004-08-31 Intertrust Technologies Corp. Methods and systems for encoding and protecting data using digital signature and watermarking techniques
US20060005021A1 (en) 1999-06-09 2006-01-05 Andres Torrubia-Saez Methods and apparatus for secure distribution of software
ATE301895T1 (en) 1999-06-10 2005-08-15 Alcatel Internetworking Inc SYSTEM AND METHOD FOR AUTOMATIC REACHABILITY UPDATE IN VIRTUAL PRIVATE NETWORKS
US6988199B2 (en) 2000-07-07 2006-01-17 Message Secure Secure and reliable document delivery
US6687822B1 (en) 1999-06-11 2004-02-03 Lucent Technologies Inc Method and system for providing translation certificates
US6393126B1 (en) 1999-06-23 2002-05-21 Datum, Inc. System and methods for generating trusted and authenticatable time stamps for electronic documents
US6754665B1 (en) 1999-06-24 2004-06-22 Sony Corporation Information processing apparatus, information processing method, and storage medium
US7188181B1 (en) 1999-06-30 2007-03-06 Sun Microsystems, Inc. Universal session sharing
US6240188B1 (en) 1999-07-06 2001-05-29 Matsushita Electric Industrial Co., Ltd. Distributed group key management scheme for secure many-to-many communication
KR100751199B1 (en) 1999-07-06 2007-08-22 소니 가부시끼 가이샤 Management device and data processing device
US6477544B1 (en) 1999-07-16 2002-11-05 Microsoft Corporation Single instance store for file systems
US6389433B1 (en) 1999-07-16 2002-05-14 Microsoft Corporation Method and system for automatically merging files into a single instance store
US6598161B1 (en) 1999-08-09 2003-07-22 International Business Machines Corporation Methods, systems and computer program products for multi-level encryption
US6308256B1 (en) 1999-08-18 2001-10-23 Sun Microsystems, Inc. Secure execution of program instructions provided by network interactions with processor
US6339423B1 (en) 1999-08-23 2002-01-15 Entrust, Inc. Multi-domain access control
US6785810B1 (en) 1999-08-31 2004-08-31 Espoc, Inc. System and method for providing secure transmission, search, and storage of data
US6363480B1 (en) 1999-09-14 2002-03-26 Sun Microsystems, Inc. Ephemeral decryptability
US6987752B1 (en) 1999-09-15 2006-01-17 Lucent Technologies Inc. Method and apparatus for frequency offset estimation and interleaver synchronization using periodic signature sequences
US7319986B2 (en) 1999-09-28 2008-01-15 Bank Of America Corporation Dynamic payment cards and related management systems and associated methods
US6446090B1 (en) 1999-10-08 2002-09-03 Unisys Corporation Tracker sensing method for regulating synchronization of audit files between primary and secondary hosts
US6836463B2 (en) 1999-10-15 2004-12-28 Nokia Corporation System for communicating labeled routing trees to establish preferred paths and source routes with local identifiers in wireless computer networks
US6961849B1 (en) * 1999-10-21 2005-11-01 International Business Machines Corporation Selective data encryption using style sheet processing for decryption by a group clerk
US6683954B1 (en) * 1999-10-23 2004-01-27 Lockstream Corporation Key encryption using a client-unique additional key for fraud prevention
DE19952527C2 (en) 1999-10-30 2002-01-17 Ibrixx Ag Fuer Etransaction Ma Process and transaction interface for secure data exchange between distinguishable networks
US6611846B1 (en) 1999-10-30 2003-08-26 Medtamic Holdings Method and system for medical patient data analysis
CA2287871C (en) 1999-11-01 2007-07-31 Ibm Canada Limited-Ibm Canada Limitee Secure document management system
US6301614B1 (en) 1999-11-02 2001-10-09 Alta Vista Company System and method for efficient representation of data set addresses in a web crawler
US7003560B1 (en) 1999-11-03 2006-02-21 Accenture Llp Data warehouse computing system
JP2001357312A (en) 1999-11-24 2001-12-26 Sega Corp Information processor, file server, method and system for charging management, and recording medium with program recorded
JP2001216226A (en) 1999-11-26 2001-08-10 Mitsubishi Electric Corp Inter-application data transmission/reception system and method threfor, and computer-readable recording medium having program for making computer operate inter-application data transmission/reception method recording thereon
WO2001041000A1 (en) 1999-11-30 2001-06-07 New Media Technology, Corp. System and method for computer-assisted manual and automatic logging of time-based media
EP1107504B1 (en) 1999-12-02 2007-03-21 International Business Machines Corporation Method of updating encryption keys in a data communication system
US7308702B1 (en) 2000-01-14 2007-12-11 Secure Computing Corporation Locally adaptable central security management in a heterogeneous network environment
US6698022B1 (en) 1999-12-15 2004-02-24 Fujitsu Limited Timestamp-based timing recovery for cable modem media access controller
US6961855B1 (en) 1999-12-16 2005-11-01 International Business Machines Corporation Notification of modifications to a trusted computing base
JP2001175606A (en) 1999-12-20 2001-06-29 Sony Corp Data processor, and data processing equipment and its method
US20010034839A1 (en) 1999-12-24 2001-10-25 Guenter Karjoth Method and apparatus for secure transmission of data and applications
US6601170B1 (en) 1999-12-30 2003-07-29 Clyde Riley Wallace, Jr. Secure internet user state creation method and system with user supplied key and seeding
US7237002B1 (en) 2000-01-04 2007-06-26 International Business Machines Corporation System and method for dynamic browser management of web site
US6751573B1 (en) 2000-01-10 2004-06-15 Agilent Technologies, Inc. Performance monitoring in distributed systems using synchronized clocks and distributed event logs
US7340600B1 (en) 2000-01-14 2008-03-04 Hewlett-Packard Development Company, L.P. Authorization infrastructure based on public key cryptography
US7822683B2 (en) 2000-01-21 2010-10-26 Microsoft Corporation System and method for secure third-party development and hosting within a financial services network
US6952780B2 (en) 2000-01-28 2005-10-04 Safecom A/S System and method for ensuring secure transfer of a document from a client of a network to a printer
US7251666B2 (en) 2000-02-01 2007-07-31 Internet Business Information Group Signature loop authorizing method and apparatus
US6588673B1 (en) * 2000-02-08 2003-07-08 Mist Inc. Method and system providing in-line pre-production data preparation and personalization solutions for smart cards
US6915435B1 (en) 2000-02-09 2005-07-05 Sun Microsystems, Inc. Method and system for managing information retention
SG96597A1 (en) * 2000-02-17 2003-06-16 Ibm Archiving and retrieval method and apparatus
US7412462B2 (en) 2000-02-18 2008-08-12 Burnside Acquisition, Llc Data repository and method for promoting network storage of data
US6633311B1 (en) 2000-02-18 2003-10-14 Hewlett-Packard Company, L.P. E-service to manage and export contact information
US20020016922A1 (en) 2000-02-22 2002-02-07 Richards Kenneth W. Secure distributing services network system and method thereof
US7032241B1 (en) 2000-02-22 2006-04-18 Microsoft Corporation Methods and systems for accessing networks, methods and systems for accessing the internet
US6834341B1 (en) 2000-02-22 2004-12-21 Microsoft Corporation Authentication methods and systems for accessing networks, authentication methods and systems for accessing the internet
JP3508680B2 (en) 2000-02-24 2004-03-22 日本電気株式会社 Content illegal copy prevention method and system
US7013485B2 (en) 2000-03-06 2006-03-14 I2 Technologies U.S., Inc. Computer security system
EP1133101A1 (en) 2000-03-07 2001-09-12 BRITISH TELECOMMUNICATIONS public limited company Data distribution
US20020062245A1 (en) 2000-03-09 2002-05-23 David Niu System and method for generating real-time promotions on an electronic commerce world wide website to increase the likelihood of purchase
DE60138884D1 (en) 2000-03-10 2009-07-16 Herbert Street Technologies Lt DATA TRANSFER AND ADMINISTRATIVE PROCEDURES
JP2001256113A (en) 2000-03-13 2001-09-21 Toshiba Corp Contents processing system and contents protection method
CA2404141A1 (en) 2000-03-22 2001-09-27 Unifiedmarket Inc Method and system for a network-based securities marketplace
JP2004501532A (en) * 2000-03-29 2004-01-15 ヴァディアム テクノロジー インコーポレイテッド One-time pad encryption with central key provision and key enterable characters
US7200230B2 (en) 2000-04-06 2007-04-03 Macrovision Corporation System and method for controlling and enforcing access rights to encrypted media
EP1277101A4 (en) 2000-04-07 2005-07-20 Movielink Llc System and process for delivery of content over a network
US6718361B1 (en) 2000-04-07 2004-04-06 Network Appliance Inc. Method and apparatus for reliable and scalable distribution of data files in distributed networks
US6877043B2 (en) 2000-04-07 2005-04-05 Broadcom Corporation Method for distributing sets of collision resolution parameters in a frame-based communications network
US7124164B1 (en) 2001-04-17 2006-10-17 Chemtob Helen J Method and apparatus for providing group interaction via communications networks
US6996718B1 (en) 2000-04-21 2006-02-07 At&T Corp. System and method for providing access to multiple user accounts via a common password
US6971018B1 (en) 2000-04-28 2005-11-29 Microsoft Corporation File protection service for a computer system
US20020059144A1 (en) 2000-04-28 2002-05-16 Meffert Gregory J. Secured content delivery system and method
US6571291B1 (en) 2000-05-01 2003-05-27 Advanced Micro Devices, Inc. Apparatus and method for validating and updating an IP checksum in a network switching system
US6842769B1 (en) 2000-05-05 2005-01-11 Interland, Inc. Automatically configured network server
US6983365B1 (en) 2000-05-05 2006-01-03 Microsoft Corporation Encryption systems and methods for identifying and coalescing identical objects encrypted with different keys
US7209941B2 (en) 2000-05-11 2007-04-24 Fujitsu Limited System and method for distributing contents from a child server based on a client's current location
US6922785B1 (en) 2000-05-11 2005-07-26 International Business Machines Corporation Apparatus and a method for secure communications for network computers
EP1154348B9 (en) 2000-05-11 2007-06-13 Matsushita Electric Industrial Co., Ltd. File management apparatus
JP3597448B2 (en) 2000-05-12 2004-12-08 住友重機械工業株式会社 Information access method and network system
US6874139B2 (en) 2000-05-15 2005-03-29 Interfuse Technology Corporation Method and system for seamless integration of preprocessing and postprocessing functions with an existing application program
US7047404B1 (en) 2000-05-16 2006-05-16 Surety Llc Method and apparatus for self-authenticating digital records
US7003107B2 (en) 2000-05-23 2006-02-21 Mainstream Encryption Hybrid stream cipher
US6937561B2 (en) 2000-06-02 2005-08-30 Agere Systems Inc. Method and apparatus for guaranteeing data transfer rates and enforcing conformance with traffic profiles in a packet network
EP1209832A1 (en) 2000-06-02 2002-05-29 Matsushita Electric Industrial Co., Ltd. Information providing system and device constituting the same
JP3851493B2 (en) 2000-06-12 2006-11-29 株式会社日立製作所 Database search method, database search system, and computer-readable recording medium recording database search program
EP1218829A1 (en) 2000-06-13 2002-07-03 Lucent Technologies Inc. Methods and apparatus for providing privacy-preserving global customization
US20030061506A1 (en) 2001-04-05 2003-03-27 Geoffrey Cooper System and method for security policy
US20020093527A1 (en) 2000-06-16 2002-07-18 Sherlock Kieran G. User interface for a security policy system and method
US20030005407A1 (en) 2000-06-23 2003-01-02 Hines Kenneth J. System and method for coordination-centric design of software systems
KR100358387B1 (en) 2000-06-27 2002-10-25 엘지전자 주식회사 Apparatus for extended firewall protecting internal resources in network system
US7035910B1 (en) 2000-06-29 2006-04-25 Microsoft Corporation System and method for document isolation
US7099926B1 (en) 2000-07-06 2006-08-29 International Business Machines Corporation Object caching and update queuing technique to improve performance and resource utilization
WO2002005061A2 (en) 2000-07-06 2002-01-17 David Paul Felsher Information record infrastructure, system and method
US7080077B2 (en) 2000-07-10 2006-07-18 Oracle International Corporation Localized access
US7194764B2 (en) 2000-07-10 2007-03-20 Oracle International Corporation User authentication
AU2001286145A1 (en) 2000-07-10 2002-01-21 It Masters Technologies S.A. System and method of enterprise systems and business impact management
AU7593601A (en) 2000-07-14 2002-01-30 Atabok Inc Controlling and managing digital assets
JP4660899B2 (en) 2000-07-24 2011-03-30 ソニー株式会社 Data processing apparatus, data processing method, and program providing medium
US6968456B1 (en) 2000-08-08 2005-11-22 Novell, Inc. Method and system for providing a tamper-proof storage of an audit trail in a database
CA2418740C (en) * 2000-08-08 2010-07-27 Wachovia Corporation Internet third-party authentication using electronic tickets
US20020031230A1 (en) 2000-08-15 2002-03-14 Sweet William B. Method and apparatus for a web-based application service model for security management
US6947556B1 (en) 2000-08-21 2005-09-20 International Business Machines Corporation Secure data storage and retrieval with key management and user authentication
US7197638B1 (en) 2000-08-21 2007-03-27 Symantec Corporation Unified permissions control for remotely and locally stored files whose informational content may be protected by smart-locking and/or bubble-protection
EP1182874A1 (en) 2000-08-24 2002-02-27 Canal+ Technologies Société Anonyme Digital content protection system
US20020052981A1 (en) 2000-08-31 2002-05-02 Fujitsu Limited Method for suppressing a menu, method for controlling copying and moving of data and computer-readable recording medium recorded with program code for controlling a menu
JP4269501B2 (en) 2000-09-07 2009-05-27 ソニー株式会社 Information recording apparatus, information reproducing apparatus, information recording method, information reproducing method, information recording medium, and program providing medium
JP4595182B2 (en) 2000-09-07 2010-12-08 ソニー株式会社 Information recording apparatus, information reproducing apparatus, information recording method, information reproducing method, information recording medium, and program providing medium
US6691227B1 (en) 2000-09-08 2004-02-10 Reefedge, Inc. Location-independent packet routing and secure access in a short-range wireless networking environment
US6941355B1 (en) 2000-09-08 2005-09-06 Bbnt Solutions Llc System for selecting and disseminating active policies to peer device and discarding policy that is not being requested
US6915425B2 (en) 2000-12-13 2005-07-05 Aladdin Knowledge Systems, Ltd. System for permitting off-line playback of digital content, and for managing content rights
US20020046350A1 (en) 2000-09-14 2002-04-18 Lordemann David A. Method and system for establishing an audit trail to protect objects distributed over a network
US6826698B1 (en) 2000-09-15 2004-11-30 Networks Associates Technology, Inc. System, method and computer program product for rule based network security policies
KR20020022317A (en) 2000-09-19 2002-03-27 윤종용 Home gateway and Method for operating the same
US6976259B1 (en) 2000-09-29 2005-12-13 Microsoft Corporation Method for abstract state transitions without requiring state machine knowledge
US7082538B2 (en) 2000-10-03 2006-07-25 Omtool, Ltd. Electronically verified digital signature and document delivery system and method
US7249044B2 (en) 2000-10-05 2007-07-24 I2 Technologies Us, Inc. Fulfillment management system for managing ATP data in a distributed supply chain environment
US20020089602A1 (en) 2000-10-18 2002-07-11 Sullivan Gary J. Compressed timing indicators for media samples
JP2002132583A (en) 2000-10-20 2002-05-10 Sony Corp Data processing apparatus, data storage device and data processing method, and program providing medium
US7362868B2 (en) 2000-10-20 2008-04-22 Eruces, Inc. Hidden link dynamic key manager for use in computer systems with database structure for storage of encrypted data and method for storage and retrieval of encrypted data
US20020050098A1 (en) 2000-10-28 2002-05-02 Chan Kwon Kyong Rotary access locking apparatus
US20020112035A1 (en) 2000-10-30 2002-08-15 Carey Brian M. System and method for performing content experience management
US6988133B1 (en) 2000-10-31 2006-01-17 Cisco Technology, Inc. Method and apparatus for communicating network quality of service policy information to a plurality of policy enforcement points
GB0027280D0 (en) 2000-11-08 2000-12-27 Malcolm Peter An information management system
JP3784635B2 (en) 2000-11-10 2006-06-14 富士通株式会社 Data operation method
US7140044B2 (en) 2000-11-13 2006-11-21 Digital Doors, Inc. Data security system and method for separation of user communities
US7660902B2 (en) 2000-11-20 2010-02-09 Rsa Security, Inc. Dynamic file access control and management
EP1220490A1 (en) 2000-11-22 2002-07-03 Lucent Technologies Inc. Method and system for enhanced packet transmission in cellular networks
CA2327211A1 (en) 2000-12-01 2002-06-01 Nortel Networks Limited Management of log archival and reporting for data network security systems
US7277962B2 (en) 2000-12-01 2007-10-02 Fujitsu Limited Method and apparatus for packet scheduling using virtual time stamp for high capacity combined input and output queued switching system
US20020069363A1 (en) 2000-12-05 2002-06-06 Winburn Michael Lee System and method for data recovery and protection
US7356704B2 (en) 2000-12-07 2008-04-08 International Business Machines Corporation Aggregated authenticated identity apparatus for and method therefor
JP3899808B2 (en) 2000-12-07 2007-03-28 株式会社日立製作所 Digital signature generation method and digital signature verification method
US20020129235A1 (en) 2001-01-11 2002-09-12 Ryuichi Okamoto Digital data distributing system
US6978376B2 (en) 2000-12-15 2005-12-20 Authentica, Inc. Information security architecture for encrypting documents for remote access while maintaining access control
US6931450B2 (en) 2000-12-18 2005-08-16 Sun Microsystems, Inc. Direct access from client to storage device
US20020077988A1 (en) * 2000-12-19 2002-06-20 Sasaki Gary D. Distributing digital content
US6915437B2 (en) 2000-12-20 2005-07-05 Microsoft Corporation System and method for improved network security
US6816871B2 (en) 2000-12-22 2004-11-09 Oblix, Inc. Delivering output XML with dynamically selectable processing
US7058978B2 (en) 2000-12-27 2006-06-06 Microsoft Corporation Security component for a computing device
NO20006684D0 (en) 2000-12-28 2000-12-28 Abb Research Ltd Time Synchronization
US7096266B2 (en) 2001-01-08 2006-08-22 Akamai Technologies, Inc. Extending an Internet content delivery network into an enterprise
US7013332B2 (en) 2001-01-09 2006-03-14 Microsoft Corporation Distributed policy model for access control
US7496767B2 (en) 2001-01-19 2009-02-24 Xerox Corporation Secure content objects
US7047293B2 (en) 2001-02-14 2006-05-16 Ricoh Co., Ltd. Method and system of remote diagnostic, control and information collection using multiple formats and multiple protocols with delegating protocol processor
US7076067B2 (en) 2001-02-21 2006-07-11 Rpk New Zealand Limited Encrypted media key management
US7185364B2 (en) 2001-03-21 2007-02-27 Oracle International Corporation Access system interface
GB2372597B (en) 2001-02-27 2005-08-10 Hewlett Packard Co Device and method for data timestamping
US6542911B2 (en) 2001-03-01 2003-04-01 Sun Microsystems, Inc. Method and apparatus for freeing memory from an extensible markup language document object model tree active in an application cache
US20020124180A1 (en) 2001-03-02 2002-09-05 Nokia Mobile Phones Ltd. Security animation for display on portable electronic device
US20020133699A1 (en) * 2001-03-13 2002-09-19 Pueschel Roy Myron Method and apparatus to regulate use of freely exchanged files and streams
JP2002271316A (en) 2001-03-13 2002-09-20 Sanyo Electric Co Ltd Reproducing equipment
US6920558B2 (en) 2001-03-20 2005-07-19 Networks Associates Technology, Inc. Method and apparatus for securely and dynamically modifying security policy configurations in a distributed system
US7043637B2 (en) 2001-03-21 2006-05-09 Microsoft Corporation On-disk file format for a serverless distributed file system
US7478243B2 (en) 2001-03-21 2009-01-13 Microsoft Corporation On-disk file format for serverless distributed file system with signed manifest of file modifications
US7181017B1 (en) 2001-03-23 2007-02-20 David Felsher System and method for secure three-party communications
AU2002307015A1 (en) 2001-03-27 2002-10-08 Microsoft Corporation Distributed, scalable cryptographic access control
US7076633B2 (en) 2001-03-28 2006-07-11 Swsoft Holdings, Ltd. Hosting service providing platform system and method
US20020198798A1 (en) 2001-04-03 2002-12-26 Bottomline Technologies, Inc. Modular business transactions platform
US7353204B2 (en) 2001-04-03 2008-04-01 Zix Corporation Certified transmission system
JP4267925B2 (en) 2001-04-09 2009-05-27 ミュージックプレイグラウンド・インコーポレーテッド Medium for storing multipart audio performances by interactive playback
US20030037237A1 (en) 2001-04-09 2003-02-20 Jean-Paul Abgrall Systems and methods for computer device authentication
US20030088517A1 (en) 2001-04-13 2003-05-08 Xyleco, Inc. System and method for controlling access and use of private information
US20030217333A1 (en) 2001-04-16 2003-11-20 Greg Smith System and method for rules-based web scenarios and campaigns
US20020150239A1 (en) 2001-04-17 2002-10-17 Vidius Inc. Method for personalized encryption in an un-trusted environment
US7020645B2 (en) 2001-04-19 2006-03-28 Eoriginal, Inc. Systems and methods for state-less authentication
US7222231B2 (en) 2001-04-19 2007-05-22 Hewlett-Packard Development Company, L.P. Data security for distributed file systems
US20020156726A1 (en) 2001-04-23 2002-10-24 Kleckner James E. Using digital signatures to streamline the process of amending financial transactions
US7461405B2 (en) 2001-04-26 2008-12-02 Autodesk, Inc. Mixed-media data encoding
US20030037253A1 (en) 2001-04-27 2003-02-20 Arthur Blank Digital rights management system
US7200642B2 (en) 2001-04-29 2007-04-03 Geodigm Corporation Method and apparatus for electronic delivery of electronic model images
US6941456B2 (en) 2001-05-02 2005-09-06 Sun Microsystems, Inc. Method, system, and program for encrypting files in a computer system
US20020169965A1 (en) 2001-05-08 2002-11-14 Hale Douglas Lavell Clearance-based method for dynamically configuring encryption strength
US20020169963A1 (en) 2001-05-10 2002-11-14 Seder Phillip Andrew Digital watermarking apparatus, systems and methods
CA2386491A1 (en) 2001-05-16 2002-11-16 Kasten Chase Applied Research Limited System for secure electronic information transmission
US20020174109A1 (en) 2001-05-16 2002-11-21 Chandy Kanianthra Mani Event detection with concurrent data updates
US20030177378A1 (en) 2001-06-01 2003-09-18 Erland Wittkotter Apparatus and method for the decryption of an encrypted electronic document
US7280658B2 (en) 2001-06-01 2007-10-09 International Business Machines Corporation Systems, methods, and computer program products for accelerated dynamic protection of data
EP1436682B1 (en) 2001-06-15 2015-09-02 Link Us All, Llc System and method for specifying security, privacy, and access control to information used by others
EP1413094B1 (en) 2001-06-27 2007-08-15 Hyglo Systems AB Distributed server functionality for emulated lan
US20030005168A1 (en) 2001-06-29 2003-01-02 Leerssen Scott Alan System and method for auditing system call events with system call wrappers
US7962950B2 (en) 2001-06-29 2011-06-14 Hewlett-Packard Development Company, L.P. System and method for file system mandatory access control
US7313824B1 (en) 2001-07-13 2007-12-25 Liquid Machines, Inc. Method for protecting digital content from unauthorized use by automatically and dynamically integrating a content-protection agent
US6957261B2 (en) 2001-07-17 2005-10-18 Intel Corporation Resource policy management using a centralized policy data structure
KR20010088917A (en) 2001-07-30 2001-09-29 최종욱 Method of protecting digital information and system thereof
US20030028610A1 (en) 2001-08-03 2003-02-06 Pearson Christopher Joel Peer-to-peer file sharing system and method using user datagram protocol
ATE465571T1 (en) 2001-08-13 2010-05-15 Univ Leland Stanford Junior SYSTEMS AND METHODS FOR IDENTITY-BASED ENCRYPTION AND RELATED CRYPTOGRAPHIC TECHNIQUES
US6745209B2 (en) 2001-08-15 2004-06-01 Iti, Inc. Synchronization of plural databases in a database replication system
US20030037133A1 (en) 2001-08-15 2003-02-20 Thomas Owens Method and system for implementing redundant servers
US6754657B2 (en) 2001-08-24 2004-06-22 Microsoft Corporation Time stamping of database records
US7729495B2 (en) 2001-08-27 2010-06-01 Dphi Acquisitions, Inc. System and method for detecting unauthorized copying of encrypted data
US6993790B2 (en) 2001-08-30 2006-01-31 International Business Machines Corporation Host-based systematic attack detection tool
US7454446B2 (en) 2001-08-31 2008-11-18 Rocket Software, Inc. Techniques for storing data based upon storage policies
US7092977B2 (en) 2001-08-31 2006-08-15 Arkivio, Inc. Techniques for storing data based upon storage policies
US20030046176A1 (en) 2001-09-04 2003-03-06 Hynes Harold F. One page purchasing system
US6892201B2 (en) 2001-09-05 2005-05-10 International Business Machines Corporation Apparatus and method for providing access rights information in a portion of a file
US20030051039A1 (en) * 2001-09-05 2003-03-13 International Business Machines Corporation Apparatus and method for awarding a user for accessing content based on access rights information
US20050021467A1 (en) 2001-09-07 2005-01-27 Robert Franzdonk Distributed digital rights network (drn), and methods to access operate and implement the same
US7134041B2 (en) 2001-09-20 2006-11-07 Evault, Inc. Systems and methods for data backup over a network
US7574501B2 (en) 2001-09-25 2009-08-11 Siebel Systems, Inc. System and method for configuring and viewing audit trails in an information network
US7359517B1 (en) 2001-10-09 2008-04-15 Adobe Systems Incorporated Nestable skeleton decryption keys for digital rights management
JP4608212B2 (en) 2001-10-12 2011-01-12 ジオトラスト インコーポレーテッド Automatic authentication processing and digital certificate issuing method and system
US7496645B2 (en) 2001-10-18 2009-02-24 Hewlett-Packard Development Company, L.P. Deployment of business logic software and data content onto network servers
IL146136A0 (en) 2001-10-24 2002-07-25 Netlink I T Solutions Ltd Data processing system and development tool
US6877136B2 (en) 2001-10-26 2005-04-05 United Services Automobile Association (Usaa) System and method of providing electronic access to one or more documents
US7200747B2 (en) 2001-10-31 2007-04-03 Hewlett-Packard Development Company, L.P. System for ensuring data privacy and user differentiation in a distributed file system
US7171557B2 (en) 2001-10-31 2007-01-30 Hewlett-Packard Development Company, L.P. System for optimized key management with file groups
US7203317B2 (en) 2001-10-31 2007-04-10 Hewlett-Packard Development Company, L.P. System for enabling lazy-revocation through recursive key generation
US20030088783A1 (en) 2001-11-06 2003-05-08 Dipierro Massimo Systems, methods and devices for secure computing
US7028300B2 (en) 2001-11-13 2006-04-11 Microsoft Corporation Method and system for managing resources in a distributed environment that has an associated object
US6865555B2 (en) 2001-11-21 2005-03-08 Digeo, Inc. System and method for providing conditional access to digital content
US20030101072A1 (en) 2001-11-28 2003-05-29 Dick John D. Document protection system
US6735213B2 (en) 2001-11-28 2004-05-11 Thinkengine Networks Inc. Processing of telephony samples
US7225256B2 (en) 2001-11-30 2007-05-29 Oracle International Corporation Impersonation in an access system
US20030110266A1 (en) 2001-12-10 2003-06-12 Cysive, Inc. Apparatus and method of using session state data across sessions
US7159036B2 (en) 2001-12-10 2007-01-02 Mcafee, Inc. Updating data from a source computer to groups of destination computers
US7565683B1 (en) 2001-12-12 2009-07-21 Weiqing Huang Method and system for implementing changes to security policies in a distributed security system
US7380120B1 (en) 2001-12-12 2008-05-27 Guardian Data Storage, Llc Secured data format for access control
US20030154381A1 (en) 2002-02-12 2003-08-14 Pervasive Security Systems, Inc. Managing file access via a designated place
US7478418B2 (en) 2001-12-12 2009-01-13 Guardian Data Storage, Llc Guaranteed delivery of changes to security policies in a distributed system
US6889210B1 (en) 2001-12-12 2005-05-03 Pss Systems, Inc. Method and system for managing security tiers
US20030110169A1 (en) 2001-12-12 2003-06-12 Secretseal Inc. System and method for providing manageability to security information for secured items
US7562232B2 (en) 2001-12-12 2009-07-14 Patrick Zuili System and method for providing manageability to security information for secured items
US10033700B2 (en) 2001-12-12 2018-07-24 Intellectual Ventures I Llc Dynamic evaluation of access rights
US7178033B1 (en) 2001-12-12 2007-02-13 Pss Systems, Inc. Method and apparatus for securing digital assets
US20170118214A1 (en) 2001-12-12 2017-04-27 Pervasive Security Systems, Inc. Method and architecture for providing access to secured data from non-secured clients
US7681034B1 (en) 2001-12-12 2010-03-16 Chang-Ping Lee Method and apparatus for securing electronic data
US7783765B2 (en) 2001-12-12 2010-08-24 Hildebrand Hal S System and method for providing distributed access control to secured documents
US7260555B2 (en) 2001-12-12 2007-08-21 Guardian Data Storage, Llc Method and architecture for providing pervasive security to digital assets
US7631184B2 (en) 2002-05-14 2009-12-08 Nicholas Ryan System and method for imposing security on copies of secured items
US20030115570A1 (en) 2001-12-13 2003-06-19 International Business Machines Corporation Development environment for building software applications that mimics the target environment
KR100445906B1 (en) 2001-12-14 2004-08-25 주식회사 이지 Isolator/circulator having a propeller resonator symmetrically loaded with many magnetic walls
US7024427B2 (en) 2001-12-19 2006-04-04 Emc Corporation Virtual file system
JP2003189232A (en) 2001-12-21 2003-07-04 Mitsubishi Electric Corp Recorded mpeg data selection device and mpeg data recording device
KR100463842B1 (en) 2001-12-27 2004-12-29 한국전자통신연구원 Apparatus for managing key in afile security system and method for managing security key
US7035877B2 (en) 2001-12-28 2006-04-25 Kimberly-Clark Worldwide, Inc. Quality management and intelligent manufacturing with labels and smart tags in event-based product manufacturing
US7703046B2 (en) 2002-01-09 2010-04-20 American Power Conversion Corporation User interface providing UPS information
US6681990B2 (en) 2002-05-31 2004-01-27 Sap Aktiengesellschaft Item tracking systems and real-time inventory management
WO2003067473A1 (en) 2002-02-04 2003-08-14 Cataphora, Inc. A method and apparatus for sociological data mining
US8176334B2 (en) 2002-09-30 2012-05-08 Guardian Data Storage, Llc Document security system that permits external users to gain access to secured files
US6807636B2 (en) 2002-02-13 2004-10-19 Hitachi Computer Products (America), Inc. Methods and apparatus for facilitating security in a network
US7698230B1 (en) 2002-02-15 2010-04-13 ContractPal, Inc. Transaction architecture utilizing transaction policy statements
US20030159066A1 (en) 2002-02-15 2003-08-21 Kdms International Llc Method and apparatus for network user location verification
JP2003244139A (en) 2002-02-20 2003-08-29 Amano Corp Time stamp imprinting system to electronic document, and program medium thereof
JP2003244128A (en) 2002-02-21 2003-08-29 Hitachi Ltd Semiconductor for encryption decoding communication and recording/reproducing apparatus
US6874089B2 (en) 2002-02-25 2005-03-29 Network Resonance, Inc. System, method and computer program product for guaranteeing electronic transactions
US20040205576A1 (en) 2002-02-25 2004-10-14 Chikirivao Bill S. System and method for managing Knowledge information
JP2003248611A (en) 2002-02-26 2003-09-05 Hitachi Ltd Storage management integration system and its storage management control method
WO2003071850A2 (en) 2002-02-28 2003-09-04 Vidius Inc. A system and method for monitoring unauthorized dissemination of documents and portable media
US7126957B1 (en) 2002-03-07 2006-10-24 Utstarcom, Inc. Media flow method for transferring real-time data between asynchronous and synchronous networks
US6845452B1 (en) 2002-03-12 2005-01-18 Reactivity, Inc. Providing security for external access to a protected computer network
US7350698B2 (en) 2002-03-15 2008-04-01 Sun Microsystems, Inc. Line item approval processing in an electronic purchasing system and method
US8332650B2 (en) 2002-03-22 2012-12-11 Microsoft Corporation Systems and methods for setting and resetting a password
US7293102B2 (en) 2002-03-26 2007-11-06 Hewlett-Packard Development Company Method and apparatus for storing data and replaying stored data in a temporally accurate manner
US7131071B2 (en) 2002-03-29 2006-10-31 Siebel Systems, Inc. Defining an approval process for requests for approval
US6938042B2 (en) 2002-04-03 2005-08-30 Laplink Software Inc. Peer-to-peer file sharing
US20030196096A1 (en) 2002-04-12 2003-10-16 Sutton James A. Microcode patch authentication
US6931597B1 (en) 2002-04-17 2005-08-16 Pss Systems, Inc. Indications of secured digital assets
US7680820B2 (en) 2002-04-19 2010-03-16 Fuji Xerox Co., Ltd. Systems and methods for displaying text recommendations during collaborative note taking
US20050071657A1 (en) 2003-09-30 2005-03-31 Pss Systems, Inc. Method and system for securing digital assets using time-based security criteria
US7748045B2 (en) 2004-03-30 2010-06-29 Michael Frederick Kenrich Method and system for providing cryptographic document retention with off-line access
US8613102B2 (en) 2004-03-30 2013-12-17 Intellectual Ventures I Llc Method and system for providing document retention using cryptography
US7035854B2 (en) 2002-04-23 2006-04-25 International Business Machines Corporation Content management system and methodology employing non-transferable access tokens to control data access
US6983353B2 (en) 2002-04-29 2006-01-03 Emc Corporation Method and apparatus for enhancing operations in disk array storage devices
US7146359B2 (en) 2002-05-03 2006-12-05 Hewlett-Packard Development Company, L.P. Method and system for filtering content in a discovered topic
US7219230B2 (en) 2002-05-08 2007-05-15 Hewlett-Packard Development Company, L.P. Optimizing costs associated with managing encrypted data
US20030217264A1 (en) 2002-05-14 2003-11-20 Signitas Corporation System and method for providing a secure environment during the use of electronic documents and data
US7246232B2 (en) 2002-05-31 2007-07-17 Sri International Methods and apparatus for scalable distributed management of wireless virtual private networks
US7000150B1 (en) 2002-06-12 2006-02-14 Microsoft Corporation Platform for computer process monitoring
US7721216B2 (en) 2002-06-18 2010-05-18 Microsoft Corporation Visual group interface for group connectivity
GB0215524D0 (en) 2002-07-05 2002-08-14 Hewlett Packard Co Method and apparatus for generating a cryptographic key
US6931530B2 (en) 2002-07-22 2005-08-16 Vormetric, Inc. Secure network file access controller implementing access control and auditing
US7076312B2 (en) 2002-08-02 2006-07-11 Fisher-Rosemount Systems, Inc. Integrated electronic signatures for approval of process control and safety system software objects
US20040022390A1 (en) 2002-08-02 2004-02-05 Mcdonald Jeremy D. System and method for data protection and secure sharing of information over a computer network
US6842825B2 (en) 2002-08-07 2005-01-11 International Business Machines Corporation Adjusting timestamps to preserve update timing information for cached data objects
US20040039781A1 (en) 2002-08-16 2004-02-26 Lavallee David Anthony Peer-to-peer content sharing method and system
US7265764B2 (en) 2002-08-27 2007-09-04 Nvidia Corporation System and method for providing a hardware icon with magnification and security
US7512810B1 (en) 2002-09-11 2009-03-31 Guardian Data Storage Llc Method and system for protecting encrypted files transmitted over a network
US7337471B2 (en) 2002-10-07 2008-02-26 Symantec Corporation Selective detection of malicious computer code
US7237024B2 (en) 2002-10-15 2007-06-26 Aol Llc Cross-site timed out authentication management
US7904720B2 (en) 2002-11-06 2011-03-08 Palo Alto Research Center Incorporated System and method for providing secure resource management
US7757075B2 (en) 2002-11-15 2010-07-13 Microsoft Corporation State reference
US7549047B2 (en) 2002-11-21 2009-06-16 Xerox Corporation Method and system for securely sharing files
US7120635B2 (en) 2002-12-16 2006-10-10 International Business Machines Corporation Event-based database access execution
US7386531B2 (en) 2002-12-19 2008-06-10 Mathon Systems, Inc. System and method for managing content
US20040254884A1 (en) 2002-12-20 2004-12-16 Sap Aktiengesellschaft Content catalog and application designer framework
US7383586B2 (en) 2003-01-17 2008-06-03 Microsoft Corporation File system operation and digital rights management (DRM)
JP4284497B2 (en) 2003-01-29 2009-06-24 日本電気株式会社 Information sharing method, apparatus, and program
US20050273600A1 (en) 2003-02-03 2005-12-08 Seeman El-Azar Method and system for file data access within a secure environment
US7003117B2 (en) * 2003-02-05 2006-02-21 Voltage Security, Inc. Identity-based encryption system for secure data distribution
US20040158586A1 (en) 2003-02-10 2004-08-12 Mingtar Tsai Method and system of using shared file for data collaboration
US20040193602A1 (en) 2003-03-28 2004-09-30 Chiu-Juan Liu Method and system for maintenance of engineering change data
US10110632B2 (en) 2003-03-31 2018-10-23 Intel Corporation Methods and systems for managing security policies
US20040199514A1 (en) 2003-04-02 2004-10-07 Ira Rosenblatt Techniques for facilitating item sharing
JP2006526337A (en) 2003-05-09 2006-11-16 松下電器産業株式会社 Reproduction apparatus and digest reproduction method
EP1629382A4 (en) 2003-06-02 2011-12-21 Liquid Machines Inc Managing data objects in dynamic, distributed and collaborative contexts
US7496959B2 (en) 2003-06-23 2009-02-24 Architecture Technology Corporation Remote collection of computer forensic evidence
US7730543B1 (en) 2003-06-30 2010-06-01 Satyajit Nath Method and system for enabling users of a group shared across multiple file security systems to access secured files
US7515717B2 (en) 2003-07-31 2009-04-07 International Business Machines Corporation Security containers for document components
US20050074124A1 (en) 2003-08-15 2005-04-07 Imcentric, Inc. Management of SSL/TLS certificates
US7555558B1 (en) 2003-08-15 2009-06-30 Michael Frederick Kenrich Method and system for fault-tolerant transfer of files across a network
US20050050098A1 (en) 2003-09-03 2005-03-03 Paul Barnett System and method for aligning data frames in time
US7107416B2 (en) 2003-09-08 2006-09-12 International Business Machines Corporation Method, system, and program for implementing retention policies to archive records
US7146388B2 (en) 2003-10-07 2006-12-05 International Business Machines Corporation Method, system, and program for archiving files
US7117322B2 (en) 2003-09-08 2006-10-03 International Business Machines Corporation Method, system, and program for retention management and protection of stored objects
US7434048B1 (en) 2003-09-09 2008-10-07 Adobe Systems Incorporated Controlling access to electronic documents
US8127366B2 (en) 2003-09-30 2012-02-28 Guardian Data Storage, Llc Method and apparatus for transitioning between states of security policies used to secure electronic documents
US7703140B2 (en) 2003-09-30 2010-04-20 Guardian Data Storage, Llc Method and system for securing digital assets using process-driven security policies
US7467415B2 (en) 2003-09-30 2008-12-16 Novell, Inc. Distributed dynamic security for document collaboration
US7103911B2 (en) 2003-10-17 2006-09-05 Voltage Security, Inc. Identity-based-encryption system with district policy information
US20050086531A1 (en) 2003-10-20 2005-04-21 Pss Systems, Inc. Method and system for proxy approval of security changes for a file security system
US7567987B2 (en) 2003-10-24 2009-07-28 Microsoft Corporation File sharing in P2P group shared spaces
US7930757B2 (en) 2003-10-31 2011-04-19 Adobe Systems Incorporated Offline access in a document control system
US20050138371A1 (en) 2003-12-19 2005-06-23 Pss Systems, Inc. Method and system for distribution of notifications in file security systems
US7702909B2 (en) 2003-12-22 2010-04-20 Klimenty Vainstein Method and system for validating timestamps
US7249251B2 (en) 2004-01-21 2007-07-24 Emc Corporation Methods and apparatus for secure modification of a retention period for data in a storage system
US7664828B2 (en) 2004-02-20 2010-02-16 Microsoft Corporation Invalid policy detection
JP4575028B2 (en) 2004-05-27 2010-11-04 株式会社日立製作所 Disk array device and control method thereof
US20050288961A1 (en) 2004-06-28 2005-12-29 Eplus Capital, Inc. Method for a server-less office architecture
US7187033B2 (en) 2004-07-14 2007-03-06 Texas Instruments Incorporated Drain-extended MOS transistors with diode clamp and methods for making the same
US7707427B1 (en) 2004-07-19 2010-04-27 Michael Frederick Kenrich Multi-level file digests
US7661124B2 (en) 2004-10-05 2010-02-09 Microsoft Corporation Rule-driven specification of web service policy
US7454021B2 (en) 2004-10-29 2008-11-18 Hewlett-Packard Development Company, L.P. Off-loading data re-encryption in encrypted data management systems
US7512814B2 (en) 2004-11-09 2009-03-31 Fortiva Inc. Secure and searchable storage system and method
JP4595589B2 (en) 2005-03-02 2010-12-08 富士ゼロックス株式会社 Document export restriction system, document export restriction method, printer driver, and printer
AU2006201428A1 (en) 2005-04-06 2006-10-26 Activldentity, Inc. Secure digital credential sharing arrangement
EP1880549A4 (en) 2005-05-12 2011-03-30 Kylintv Inc Internet protocol television
US7581029B2 (en) 2005-06-20 2009-08-25 Intel Corporation Updating machines while disconnected from an update source
US20070193397A1 (en) 2006-02-07 2007-08-23 Great Performance Industrial Co., Ltd Structure of shift lever head
US8155157B2 (en) 2006-09-22 2012-04-10 Samsung Electronics Co., Ltd. Method and apparatus for synchronizing applications of terminals in communication network
JP4608522B2 (en) 2007-07-12 2011-01-12 Sky株式会社 File management system
EP2279472A4 (en) 2008-04-05 2013-11-20 Social Communications Co Shared virtual area communication environment based apparatus and methods
US20100047757A1 (en) 2008-08-22 2010-02-25 Mccurry Douglas System and method for using interim-assessment data for instructional decision-making

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5745573A (en) * 1994-08-11 1998-04-28 Trusted Information Systems, Inc. System and method for controlling access to a user secret
US6085323A (en) * 1996-04-15 2000-07-04 Kabushiki Kaisha Toshiba Information processing system having function of securely protecting confidential information
US6134660A (en) * 1997-06-30 2000-10-17 Telcordia Technologies, Inc. Method for revoking computer backup files using cryptographic techniques
US6292899B1 (en) * 1998-09-23 2001-09-18 Mcbride Randall C. Volatile key apparatus for safeguarding confidential data stored in a computer system memory
US6449721B1 (en) * 1999-05-28 2002-09-10 Authentica Security Technologies, Inc. Method of encrypting information for remote access while maintaining access control
US7224795B2 (en) * 1999-10-20 2007-05-29 Fujitsu Limited Variable-length key cryptosystem
US6647388B2 (en) * 1999-12-16 2003-11-11 International Business Machines Corporation Access control system, access control method, storage medium and program transmission apparatus
US6891953B1 (en) * 2000-06-27 2005-05-10 Microsoft Corporation Method and system for binding enhanced software features to a persona
US6810389B1 (en) * 2000-11-08 2004-10-26 Synopsys, Inc. System and method for flexible packaging of software application licenses

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10360545B2 (en) 2001-12-12 2019-07-23 Guardian Data Storage, Llc Method and apparatus for accessing secured electronic data off-line
US8341407B2 (en) 2001-12-12 2012-12-25 Guardian Data Storage, Llc Method and system for protecting electronic data in enterprise environment
US9542560B2 (en) 2001-12-12 2017-01-10 Intellectual Ventures I Llc Methods and systems for providing access control to secured data
US8543827B2 (en) 2001-12-12 2013-09-24 Intellectual Ventures I Llc Methods and systems for providing access control to secured data
US8918839B2 (en) 2001-12-12 2014-12-23 Intellectual Ventures I Llc System and method for providing multi-location access management to secured items
US10229279B2 (en) 2001-12-12 2019-03-12 Intellectual Ventures I Llc Methods and systems for providing access control to secured data
US9129120B2 (en) 2001-12-12 2015-09-08 Intellectual Ventures I Llc Methods and systems for providing access control to secured data
US8341406B2 (en) 2001-12-12 2012-12-25 Guardian Data Storage, Llc System and method for providing different levels of key security for controlling access to secured items
US10769288B2 (en) 2001-12-12 2020-09-08 Intellectual Property Ventures I Llc Methods and systems for providing access control to secured data
US10033700B2 (en) 2001-12-12 2018-07-24 Intellectual Ventures I Llc Dynamic evaluation of access rights
US8327138B2 (en) 2003-09-30 2012-12-04 Guardian Data Storage Llc Method and system for securing digital assets using process-driven security policies
US10630662B1 (en) 2012-05-17 2020-04-21 Amazon Technologies, Inc. Key rotation with external workflows
US9276754B1 (en) 2012-05-17 2016-03-01 Amazon Technologies, Inc. Key rotation with external workflows
US8964990B1 (en) * 2012-05-17 2015-02-24 Amazon Technologies, Inc. Automating key rotation in a distributed system
US10454676B2 (en) * 2015-02-13 2019-10-22 International Business Machines Corporation Automatic key management using enterprise user identity management
US10348727B2 (en) 2015-02-13 2019-07-09 International Business Machines Corporation Automatic key management using enterprise user identity management
US20160241397A1 (en) * 2015-02-13 2016-08-18 International Business Machines Corporation Automatic Key Management Using Enterprise User Identity Management
US11240291B2 (en) * 2015-06-16 2022-02-01 Airwatch Llc Content snip capture and sharing
US20170132427A1 (en) * 2015-11-06 2017-05-11 Océ Printing Systems GmbH & Co. KG Computer system and method to control access to encrypted files
CN106209807A (en) * 2016-07-04 2016-12-07 浪潮集团有限公司 A kind of cloud computing safety access control method based on domestic cryptographic algorithm
US10979218B2 (en) 2019-03-13 2021-04-13 International Business Machines Corporation Secret generation and share distribution
US11899802B2 (en) 2020-06-03 2024-02-13 Bank Of America Corporation System for monitoring networked computing devices with integrated electronic data encryption and decryption mechanism
US11593494B2 (en) 2020-06-03 2023-02-28 Bank Of America Corporation System for monitoring networked computing devices with integrated electronic data encryption and decryption mechanism

Also Published As

Publication number Publication date
US8006280B1 (en) 2011-08-23

Similar Documents

Publication Publication Date Title
US8006280B1 (en) Security system for generating keys from access rules in a decentralized manner and methods therefor
US7921450B1 (en) Security system using indirect key generation from access rules and methods therefor
US10769288B2 (en) Methods and systems for providing access control to secured data
US8918839B2 (en) System and method for providing multi-location access management to secured items
US7921288B1 (en) System and method for providing different levels of key security for controlling access to secured items
US7478418B2 (en) Guaranteed delivery of changes to security policies in a distributed system
US7729995B1 (en) Managing secured files in designated locations
US10360545B2 (en) Method and apparatus for accessing secured electronic data off-line
US7681034B1 (en) Method and apparatus for securing electronic data
US8266674B2 (en) Method and system for implementing changes to security policies in a distributed security system
US7783765B2 (en) System and method for providing distributed access control to secured documents
US9286484B2 (en) Method and system for providing document retention using cryptography
US20050223414A1 (en) Method and system for providing cryptographic document retention with off-line access

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION