WO2005038633A1

WO2005038633A1 - Device and method for securing and monitoring protected data

Info

Publication number: WO2005038633A1
Application number: PCT/EP2004/011338
Authority: WO
Inventors: Dierk Dohmann; Jens RÜDINGER
Original assignee: Vodafone Holding Gmbh
Priority date: 2003-10-16
Filing date: 2004-10-11
Publication date: 2005-04-28
Also published as: EP1676191A1; DE10348729A1; DE10348729B4; CN1894644A; CN100483297C

Abstract

The invention relates to a device (10) for securing and monitoring protected data (12) in a volatile and/or non-volatile data memory (14) of a data processing unit for the purpose of protecting them from unauthorized access. The inventive device is provided with access means (18) via which the protected data (12) in the data memory (14) can only be accessed via an authentication code (20) and/or authentication key. Means (110) detect any accesses to the protected data (12) irrespective of the input of the authentication code (20). The invention also relates to a method for securing and monitoring protected data (12) from unauthorized access using the inventive device (10).

Description

Setup and method for securing and monitoring protected data

Technical field

The invention relates to a device for securing and monitoring protected

Data in a volatile and or non-volatile data memory of a data processing unit against unauthorized access, wherein

(a) access means are provided via which the protected data in the data memory can only be accessed with an authorization code,

(b) means for detecting the number of authorization code entries are included, (c) means are provided for restricting access to the protected data, a restriction being made if the number of authorization code entries exceeds a reference value assigned to this time interval within a certain time interval,

The invention further relates to a method for securing and monitoring protected data (12) against unauthorized access with a device (10) according to one of the preceding claims, wherein (a) the number of authorization code entries for accessing the protected data (12) is determined within a specific time interval (36) and

(b) this number of attempts within the determined time interval (36) is compared with a reference value, whereby

(c) access to the protected data is restricted or prevented if the number of entries within the time interval is greater than the reference value.

State of the art

Digital data is protected against unauthorized access according to cryptographic procedures to secure and prevent it. Cryptography is basically understood to be the science of researching and implementing methods for encrypting or decrypting data, in which either the encryption method or (when using more uniform

Encryption method) the keywords used are kept secret. By changing, swapping or adding characters according to certain rules, a plain text is converted into a key text and vice versa. Such cryptographic methods are e.g. applicable for the storage of data and data transmission. This is currently the most effective means of data protection to make information that has fallen into the wrong hands worthless. In addition to confidentiality through the encryption of plain text, the methods of cryptography can also ensure the authenticity of a message and the integrity of a file, whereby the latter, the integrity of a file, means the certainty of receiving a file in an unchanged form.

Attacks on cryptographically protected data can only occur through extremely frequent access to the protected data. The most varied Tried cryptographic character combinations until finally a combination fits to be able to access the data. Depending on the key length (digital code) and the cryptographic algorithm used, these accesses for unauthorized decryption are very time-consuming. If an attacker has enough time, he can theoretically crack such a code.

There are facilities, e.g. Computers known with such cryptographic methods that serve to secure protected data so that unauthorized persons cannot access the data. For this purpose, the cryptographically protected data are, for example, in a volatile data memory, for example a RAM (=

Random Access Memory) or non-volatile data storage, before, e.g. B. Hard disk, CD-ROM and EPROM (= Erasable Programmable Read Only Memory). The data can only be accessed with a suitable digital code. The code can, for example, be stored on a magnetic stripe or a chip of a "check card" and is evaluated by means of a suitable reader for access to the protected data. Only when the code verification was successful, i.e. the data can now be decrypted in particular with the key code. Then the data can be accessed. For other facilities, the key code must be entered using a keyboard. Problems can arise with such facilities in that an unauthorized person can try to crack the key code as often as required. With the key code, he finally has unauthorized access to the protected data and can possibly cause considerable damage.

The German patent DE 198 39 041 C2 describes a method for identifying and displaying states of an incorrect operation counter. The operating error counter is installed on an intelligent data carrier. If a defined number of unsuccessful attempts is made to enter an identification feature, access to the intelligent data carrier is automatically blocked. The user is not adjusted when entering the identification feature.

A method is known from European patent application EP 1 209 551 A2 to control access to a computer. A password is checked. Access is only permitted if the password is valid. Will a certain number If an incorrect password is entered within a time interval, access is prevented. The disadvantage of this method is that the password entry does not adapt to the behavior of users. For example, in the case of older people or children, there is an increasing risk that repeated wrong passwords will be entered within a time interval.

So far, a user has entered a PIN (= Personal Identification Number) or an alphanumeric code as a correction code for access to the protected data or functions. This authorized him to access the protected data or functions. A PIN is entered for identification on mobile terminals. This identification is compared with the SIM card. If the PIN was correct, the user of the mobile radio terminal is logged into a mobile radio network. From now on he is considered to be authorized in this mobile network.

Hackers are people who try to access protected data for a variety of reasons. The hackers mostly act out of a criminal energy, e.g. to access a bank or to carry out factory espionage or sabotage, on the other hand from a purely sporting nature.

Theoretically, hackers can now access the protected data or functions without the SIM card. With suitable equipment, he can try to access the protected data via other channels, for example with another mobile terminal and an already authorized SIM card. He does not necessarily need the PIN for this.

Disclosure of the invention

It is therefore the task of the invention to provide a device which avoids the disadvantages of the prior art and prevents an attack on the protected data by any attempts, but which is oriented to the needs of the users. According to the invention, the object is achieved in that, in a device for securing protected data of the type mentioned at the outset, (d) means are provided with which the number of accesses to the protected data and / or functions is independent of the entry of the authorization code volatile or non-volatile data storage is determined within a certain time interval.

Furthermore, the task is carried out by a method of the type mentioned at the outset

Established where

(d) regardless of the entry of the authorization code, the number of accesses to the protected data and / or functions in the volatile or non-volatile data memory is determined within a certain time interval.

The invention is based on the principle of monitoring the number of accesses to the protected data within a time interval. It is assumed in the present invention that an authorized user also makes mistakes when entering the authorization code. The proposed measure prevents an unauthorized person from making any attempts to determine the authorization code. The device according to the invention also provides the authorized user with a time window in which he can access the protected data with a certain frequency. This requires that the accesses to the protected data are counted in the time interval. The system can be cleverly adapted to the user. Someone who usually z. B. five accesses during an access process to the encrypted data will continue to have five accesses within a time interval, since the device adapts to the user.

This was done by orienting a reference value at previous time intervals in which the user accessed the protected data. Does that give way Access behavior from previous time intervals, so access to the backed up data is restricted or completely prevented.

An advantageous aspect of the invention is that the data processing unit contains a clock generator for the work cycle, the time interval being determined by a specific one

Number of clock cycles of the clock generator can be predetermined. This measure can make a device largely independent of external timers, since the number of clock cycles determine a time interval.

It has also proven to be an advantageous embodiment of the invention if the means for recording the access to the protected data contain a counter which counts the number of accesses within the time interval. The meter reading can be used to check whether further access to the protected data is possible or whether all access options are initially blocked.

A preferred embodiment of the invention results from the fact that means for resetting the counter are provided, which reset the counter to zero when authorized access. This enables the counter to be reset, for example, after a predefined period of time has elapsed, in order to be able to access the protected data again. Advantageously, the means for

Restriction of access to the protected data set dynamically. This allows the restriction to be adapted to specific user profiles, if necessary. For people who access the protected data more frequently, the number of permitted accesses to the protected data within the time interval for the number of possible accesses will be higher than for groups of people who do not have such a high number. It is therefore advantageous if the means for restricting access to the protected data are designed to be adjustable to a user.

A further advantageous embodiment of the invention results from the fact that the

Data storage is provided on a SIM card. Such a device can therefore also be used in a suitable manner, for example in mobile radio terminals or telematics devices. Here are mobile terminals and telematics devices advantageously designed as a data processing unit. Alternatively, in a further embodiment of the invention, the data processing unit is designed as a computer. A preferred embodiment of the invention results from alarm means which generate an alarm signal when a number of unauthorized or incorrect accesses are exceeded. This can be used to signal that a

Unauthorized persons can tamper with the protected data.

In one embodiment of the method according to the invention, the number of accesses to the protected data is recorded with a counter within a specific time interval. This measure ensures that the number of accesses is recorded so that an event can occur if a number is exceeded in the time interval. Such an event consists in a further preferred embodiment of the method according to the invention for securing and monitoring protected data, namely when access to the protected data is restricted. This happens e.g. if a reference value for the number of accesses to the protected is exceeded

Data within a certain time interval.

Furthermore, in a special embodiment of the method according to the invention, the counter for counting the number of accesses can be reset when the access is correct. This ensures that after incorrect access

Authorized persons can access the protected data again.

Different users have their own user profile. It may be that, for example, in the case of mobile terminals, e.g. older people and possibly children have a higher error rate when accessing the protected data. It is therefore an advantageous embodiment if the number of accesses for the restriction can be set and / or adapted to a user.

An advantageous embodiment of the method according to the invention also results if the number of. Accesses for restriction over a network, in particular

Mobile network, set and / or adapted to a user. This means that the user does not necessarily have to go with his facility to a service that adjusts the facility to his needs. A preferred embodiment of the method according to the invention for securing protected data against unauthorized access results from the fact that a suitable alarm signal is generated when a value for the number of accesses to the protected data is exceeded. The alarm signal is advantageously not recognizable for the person accessing the protected data. As a result, the unauthorized person may be caught "red-handed".

In a suitable embodiment of the method according to the invention, if a value for the number of accesses to the protected data is exceeded, further access to the data is denied within a time interval. This means that access to the protected data is only blocked for a certain period of time, so that, for example, "hacker programs" by unauthorized persons have a hard time breaking into such a system. You cannot start as many attempts as you like, but have to wait for the time period before you can switch back to the protected ones

Can access data.

Further advantages result from the subject matter of the subclaims and the drawing with the associated description.

Brief description of the drawing

1 shows a schematic diagram of an inventive device for securing and monitoring protected data.

Preferred embodiment

1 shows a schematic diagram of a preferred exemplary embodiment of a device 10 according to the invention for securing and monitoring protected data 12. The protected data 12 are located in a data memory 14 of the device 10 and are identified by crossed hatching. The dates 12 are available in a coded or encrypted form according to a cryptographic process. In the present exemplary embodiment, the data memory 14 is a non-volatile memory, which can also be provided on a SIM card (= subscriber identification module).

In the present exemplary embodiment, the device 10 according to the invention is located in a data processing unit that is not explicitly shown, for example a computer or a comparable processor-controlled device, such as mobile radio terminals or telematics devices with conventional standardized interfaces 16, which are designed for data access.

Via access means 18, for example a computer keyboard, an authorization code 20 can be entered as a digital key, which is therefore symbolically represented as a key. The authorization code 20 is passed to a test unit 22. The test unit 22 is in turn in one

Authorization apparatus 23. If the authorization code 20 is correct, a decryption unit 26 decodes the protected data 12 from the data memory 14 and sends it to an output interface 28. The authorization code 26 may under certain circumstances be required in whole or in part for the decryption unit 26 to decrypt the protected data 12.

For example, a monitor, printer or other computer or storage drive (not shown) can be provided on the output interface 28 in order to display or save the decrypted data 12. The data or authorization code transmission between the individual units 18, 22, 26 or interfaces 16, 28 takes place via a data bus 30. The processes in the device 10 are controlled with the aid of a processor 32 (CPU), which has a clock generator 34 is clocked.

The clock generator 34 also serves to define a time measure 36 for the authorization apparatus 23. A number of clock cycles of the clock generator 34 that can be set by means of adjusting means 38 forms a time interval. A counter 40 counts the attempts to make incorrect entries for the authorization code 20 in order to be able to access the protected data 12. If a predetermined number of accesses for the input by the test unit 22 are determined within a set time interval 36, no further accesses via this interface 16 to the protected data 12 are permitted. This reference value for the number of possible accesses is calculated from time intervals 36, previous input attempts. For example, by recording the average number of previous authorization code entries per time interval 36. By using a reference value, which is calculated from previous input attempts, greater flexibility for the user is achieved.

Above all, however, it is primarily prevented that, in particular, computer programs of unauthorized users test a wide variety of code combinations until the correct authorization code is reached. By restricting the access, a "hacking" of the authorization code 20 is almost prevented. Access to the protected data 12 is granted when the predetermined number for entering the

Authorization codes 20 blocked within the time interval 36 for a certain period of time or even completely. An alarm signal can also be generated to signal that the number of failed attempts to enter the authorization code has been exceeded

Only an "administrator" can reset the counter 40 for the failed attempts with a suitable "reset function" 42. Alternatively, the counter 40 is reset after a predefined period of time. The time period for the access restriction can also be dynamically adjusted to the possible user habits.

For the purpose of espionage or sabotage, for example, a hacker 100 can attempt to access the protected data 12 via a further interface 102, specifically regardless of the authorization code entry described above. In order to decrypt the protected data 12, however, he must know the DecMfMeral algorithm 104. In order to get this out, he will access the protected data 12 via data bus 106. The frequency of accesses per time interval 108 is likely to be considerably higher than is the case with an authorized user. To access the protected A control unit 110 is provided to control data. The control unit 110 contains a counter 112, which counts the number of accesses to the protected data 12. The control unit 110 also contains actuating means 114. The actuating means 114 are used to set a time measure 116 for the control unit 110 via the clock generator 34. A number of clock cycles of the clock generator 34, which can be set by means of the adjusting means 114, is formed

Time interval 108. A counter 118 counts the number of accesses to the protected data 12.

If, within a set time interval 108, a predetermined number of accesses for the input by test unit 120 are determined, no further access is made

Accesses the protected data 12 more allowed. This reference value for the number of possible accesses is calculated from time intervals 108, previous accesses. For example, by recording the average number of previous accesses to the protected data 12 per time interval 108. By using a reference value, which is calculated from previous accesses per time interval, greater flexibility for the user is achieved.

If the test unit 120 determines that the number of accesses to the protected data has increased, an alarm 122 is triggered. If the accesses are below a reference value within a time interval, the counter 112 is reset.

The "administrator" can also use the "reset function" 42 to reset the counter 112 for accessing the protected data 112. Alternatively, the counter 112 is reset after a predefined period of time has elapsed.

Claims

claims

Device (10) for securing and monitoring protected data (12) in a volatile and / or non-volatile data memory (14) of a data processing unit against unauthorized access, wherein

(a) access means (18) are provided, via which the protected data (12) in the data memory (14) can be accessed only with an authorization code (20),

(b) means (23) for detecting the number of authorization code entries are contained,

(c) means (23, 26) are provided for restricting access to the protected data (12), a restriction being imposed if the number of authorization code entries within a specific time interval (36) exceeds a reference value assigned to this time interval,

characterized in that

(d) Means (110) are provided with which the number of accesses to the protected data (12) and / or functions in the volatile or non-volatile data memory (14) within a certain time interval, regardless of the entry of the authorization code (20) (108) is determined.

Device (10) for securing and monitoring protected data (12) in a data memory (14) of a data processing unit against unauthorized access according to Claim 1, characterized by means (120) for determining a Reference value from the number of accesses to the protected data (12) and / or functions per time interval (108) from previous time intervals (108).

3. Device (10) for securing and monitoring protected data (12) in a data memory (14) of a data processing unit against unauthorized access according to one of claims 1 or 2, characterized in that the data processing unit contains a clock generator (34) for the work cycle , The time interval (108) being designed to be predeterminable by a certain number of clock cycles of the clock generator (34).

4. A device (10) for securing and monitoring protected data (12) in a data memory (14) of a data processing unit against unauthorized access according to one of claims 1 to 3, characterized in that the means (110) for detecting access to the protected data 12 contain a counter (112) which counts the number of accesses within the time interval (108).

5. A device (10) for securing and monitoring protected data (12) in a data memory (14) of a data processing unit according to claim 4, characterized in that means (42) are provided for resetting the counter (112), which counter (112) 112) set to zero for authorized access.

6. Device (10) for securing and monitoring protected data (12) in a data memory (14) of a data processing unit according to one of claims 1 to 5, characterized in that means (110) for restricting access to the protected data (12 ) are set dynamically.

7. Device (10) for securing and monitoring protected data (12) in a data memory (14) of a data processing unit according to one of claims 1 to 6, characterized in that means (110) for restricting access to the protected data (12 ) are designed to be adjustable to a user profile.

8. Device (10) for securing and monitoring protected data (12) in a data memory (14) of a data processing unit according to one of claims 1 to 1, characterized in that the data memory (14) is provided on a SIM card.

9. Device (10) for securing and monitoring protected data (12) in a data memory (14) of a data processing unit according to one of claims 1 to 8, characterized in that the data processing unit is designed as a mobile radio terminal or telematics terminal.

10. Device (10) for securing and monitoring protected data (12) in a data memory (14) of a data processing unit according to one of claims 1 to 9, characterized in that the data processing unit is designed as a computer.

11. Device (10) for securing and monitoring protected data (12) in a data memory (14) of a data processing unit according to one of claims 1 to 10, characterized in that alarm means (112) are provided which, when a reference value for the Number of accesses to the protected data (12) generate an alarm signal.

12. A method for securing and monitoring protected data (12) against unauthorized access with a device (10) according to one of the preceding claims, wherein

(a) the number of authorization code entries for the access to the protected data (12) is determined within a certain time interval (36) and (b) this number of attempts within the certain time interval (36) is compared with a reference value, whereby (c) access to the protected data is restricted or prevented if the number of entries within the time interval is greater than the reference value, characterized in that

(d) regardless of the entry of the authorization code (20), the number of accesses to the protected data (12) and / or functions in the volatile or non-volatile data memory (14) is determined within a certain time interval (108).

13. A method for securing and monitoring protected data (12) against unauthorized access according to spoke 12, characterized in that a reference value is calculated from the number of accesses to the protected data (12) of previous time intervals (108).

14. A method for securing and monitoring protected data (12) against unauthorized access according to spoke 13, characterized in that the access to the protected data (12) is restricted if the number of accesses to the protected data (12) within one determined time interval (108) exceeds a reference value.

15. A method for securing and monitoring protected data (12) against unauthorized access according to one of claims 12 to 14, characterized in that the counter (112) for counting the number of accesses to the protected data (12), with a correct access , is reset.

16. A method for securing and monitoring protected data (12) against unauthorized access according to one of claims 12 to 15, characterized in that the possible number of accesses to the protected data (12) is set for the restriction and or adapted to a user profile becomes.

17. A method for securing and monitoring protected data (12) against unauthorized access according to one of claims 12 to 16, characterized in that the possible number of accesses for the restriction via a network, in particular a mobile radio network, is set and / or to a user profile is adjusted.

18. A method for securing and monitoring protected data (12) against unauthorized access according to one of claims 12 to 17, characterized in that a suitable alarm signal is generated when a reference value for the number of accesses to the protected data (12) is exceeded.

19. A method for securing and monitoring protected data (12) against unauthorized access according to spoke 18, characterized in that the alarm signal is evaluated to generate a countermeasure.

20. A method for securing and monitoring protected data (12) against unauthorized access according to spoke 19, characterized in that the countermeasures consist in a stretch of the response time.

21. A method for securing and monitoring protected data (12) against unauthorized access according to one of claims 19 or 20, characterized in that the countermeasures consist in falsifying a result.

22. A method for securing and monitoring protected data (12) against unauthorized access according to one of claims 12 to 21, characterized in that the alarm signal for the person accessing the protected data (12) is not recognizable.

23. A method for securing and monitoring protected data (12) against unauthorized access according to one of claims 12 to 23, characterized in that when a value for the number of accesses is exceeded further access to the data (12) is refused within a time interval (36).

24. The method for securing and monitoring protected data (12) against unauthorized access according to one of claims 12 to 24, characterized in that if a value for the number of accesses is exceeded, further access to the protected data (12) is restricted for a period of time is.