WO2010069102A1

WO2010069102A1 - Moblie terminal, cipher key transmission method, decrypt method and secrecy communication realizing method

Info

Publication number: WO2010069102A1
Application number: PCT/CN2008/073537
Authority: WO
Inventors: 邓方民; 郭红星; 薛涛; 闫海清
Original assignee: 中兴通讯股份有限公司
Priority date: 2008-12-16
Filing date: 2008-12-16
Publication date: 2010-06-24

Abstract

A cipher key transmission method, a decrypting method, a secrecy communication realizing method and a mobile terminal. The cipher key transmission method comprises sending terminal generating a share key, obtaining the public key of receiving terminal stored beforehand, encrypting the share key by the public key to obtain cryptograph (S102), sending terminal carrying the cryptograph in the message which includes a field with network transmission attribute and sending the message to the receiving terminal (S104). The secrecy communication can be realized between the mobile terminals by the invention schemes, high security and low system cost can be reached.

Description

The present invention relates to the field of communications, and in particular to a key transmission method, a decryption method, a method for implementing secure communication, and a mobile terminal. BACKGROUND OF THE INVENTION When a communication content is transmitted by a signal in a communication network, there is a problem that communication content may be illegally eavesdropped. Based on this, a secret communication technique between mobile terminals occurs. In the related art, there are mainly two methods of secure communication as follows. Method 1: Add an encryption/decryption device on the interface of the terminal device, and use the device to perform encryption/decryption processing on the signal of the communication content to implement secure communication. Specifically, the method generally includes the following steps: Step 1: Convert the voice into the audio signal A by the microphone; Step 2, encrypt the audio signal A to make the encrypted audio signal B, And sending to a communication terminal 1; Step 3, the encrypted audio electrical signal B output by the communication terminal 1 is transmitted to another communication terminal 2 through the public communication network; Step 4, decrypting the encrypted audio electrical signal B output by the communication terminal 2 , making it an unencrypted audio electrical signal C, and sending it to the receiver; Step 5, converting the audio electrical signal C to voice by the receiver. In the second method, the receiving end generates a key, and uses the short message technology to perform key negotiation between the receiving end and the transmitting end, and then uses the generated key to encrypt the signal of the communication content, thereby implementing secure communication. Wherein, a typical method of the solution may include the following steps: Between the mobile terminal and the application server (the mobile terminal and the application server have been authenticated by the trusted certificate authority), the use is included in the short message The identity information in the middle and the last value of the hash chain encrypted by the trusted certificate authority public key are used as the session key of both parties for the first authentication and the call. In the subsequent communication process, only the mobile terminal includes If the length of the hash chain is greater than 0, the application server can perform a hash operation on the hash value contained in the sent short message, and compare with the currently saved hash value of the application server to verify the identity of the mobile terminal. And the hash value in the received short message is used as the new call key of both parties to inform the other party for verification identity. By performing the process of password negotiation using the short message in this way, secure communication can be performed. However, there are deficiencies in the above methods. In the first method, first, the encryption/decryption device used is relatively fixed and easily obtained by an illegal user. Once the illegal user obtains the same encryption/decryption device, the communication of all the same mobile terminals is no longer secure; The key used for each communication is a fixed same key, and the security level is not high. In the second method, first, the implementation process is complicated and inconvenient to use, and each time before the call, the short message must be sent first. Key negotiation is not efficient; secondly, the real-time performance of short messages is not strong, which is easy to cause delays, and the specific implementation process will increase the cost of additional short message communication. In view of the problem of low security and inconvenient implementation in the related art secure communication technology, an improved secure communication technology is needed. SUMMARY OF THE INVENTION The present invention has been made in view of the problems of low security and inconvenient implementation in the currently used secure communication technology existing in the related art, and the present invention aims to provide an improved secure communication technology. To solve at least one of the above problems. In order to achieve the above object, according to an aspect of the present invention, a key transmission method is provided. According to the key transmission method of the present invention, the transmitting end generates a shared key, obtains a pre-stored public key of the receiving end, and encrypts the shared key by using the public key to obtain a ciphertext; the transmitting end carries the ciphertext in the Including a message with a field with a network transparent transmission attribute, and sending the message to the receiving end. The generating a shared key by the sending end includes: The sending end generates a shared key after starting the call establishing process. In addition, after the message is sent to the receiving end, the method further includes: receiving, by the receiving end, the message, obtaining the ciphertext in the field included in the message, and decrypting the ciphertext by using the private key of the receiving end to obtain the shared key. In addition, after the message is sent to the receiving end, the method further includes: after the call is successfully established, the sending end encrypts the communication content to be transmitted by using the shared key, and sends the encrypted communication content to the receiving end. In addition, the above method further includes: the receiving end decrypting the received encrypted communication content by using the shared key. In addition, the foregoing method further includes: the receiving end uses the shared key to perform the communication content to be transmitted. Encrypt, and send the encrypted communication content to the sender. The field having the network transparent transmission attribute includes: a user information unit field in the call setup message. In order to achieve the above object, according to another aspect of the present invention, a decryption method is provided. The decryption method according to the present invention includes: the receiving end receives the message from the transmitting end including the field having the network transparent transmission attribute, and acquires the ciphertext carried in the field, where the ciphertext is the transmitting end using the public key pair of the receiving end to share the secret The key is generated by the key encryption; the receiving end decrypts the ciphertext using its own private key to obtain the shared key generated by the transmitting end; the receiving end receives the communication content encrypted by the shared key from the transmitting end, and uses the decrypted shared key. The encrypted communication content is decrypted to obtain the communication content. In addition, the foregoing method further includes: the receiving end encrypts the communication content to be transmitted by using the shared key, and sends the encrypted communication content to the sending end. In order to achieve the above object, according to still another aspect of the present invention, a method of implementing secure communication is provided. The method for implementing secure communication according to the present invention includes: the calling terminal generates a shared key while establishing a call with the called terminal, and transmits the shared key to the called terminal; after the call is established, the calling terminal And the called terminal uses the shared key to force the communication content. Secret or decrypted. In order to achieve the above object, according to still another aspect of the present invention, a mobile terminal is provided. The mobile terminal according to the present invention includes: a storage unit configured to store a public key of the opposite mobile terminal; a key generation unit configured to generate a shared key; and a ciphertext generating unit configured to acquire the public key from the storage unit, The key generation unit acquires the shared key, and uses the public key to force the shared key. The ciphertext is obtained by the ciphertext generating unit, and the ciphertext generated by the ciphertext generating unit is carried in a field having a network transparent transmission attribute, and the field is carried in the message; the notification unit is configured to use the message constructed by the constructing unit Notifying the shared mobile terminal of the shared key. In addition, the mobile terminal further includes: an encryption unit, configured to encrypt the communication content to be transmitted by using the shared key; and a sending unit, configured to send the communication content encrypted by the encryption unit to the opposite mobile terminal. In order to achieve the above object, according to still another aspect of the present invention, a mobile terminal is provided. The mobile terminal according to the present invention includes: a first receiving unit, configured to receive a message from a remote mobile terminal, where a field having a network transparent transmission attribute of the message carries a ciphertext, and the ciphertext is a mobile terminal by using the mobile terminal The public key of the terminal is obtained by encrypting the shared key; the parsing unit is configured to parse the message received by the first receiving unit to obtain the ciphertext; and the first decrypting unit is configured to parse the private key pair of the stored mobile terminal The ciphertext obtained by the unit is decrypted to obtain a shared key. In addition, the mobile terminal further includes: a second receiving unit, configured to receive communication content from the opposite mobile terminal, where the communication content is encrypted by the opposite mobile terminal using a shared key; and the second decryption unit is configured to use The shared key obtained by a decryption unit decrypts the communication content received by the second receiving unit. According to the above technical solution of the present invention, the secret end is obtained by using the public key of the receiving end to encrypt the shared key generated by the transmitting end to obtain the ciphertext and transmitting the ciphertext, and encrypting the communication content by using the shared key, thereby realizing the confidentiality between the mobile terminals. The communication can solve the problem that the related art cannot safely and easily implement the secure communication between the mobile terminals, and the security is high and the system overhead is small. Other features and advantages of the invention will be set forth in the description which follows, and The objectives and other advantages of the invention will be realized and attained by the <RTI BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a flow chart of a key transmission method according to a first embodiment of the method of the present invention; FIG. 2 is a signaling flow chart of a key transmission method according to a preferred embodiment of the present invention; Is a flowchart of a decryption method according to a second embodiment of the method of the present invention; FIG. 4 is a signaling flow chart of a decryption method according to a preferred embodiment of the present invention; FIG. 5 is a structure of a mobile terminal according to a first embodiment of the apparatus of the present invention. Figure 6 is a block diagram showing a preferred structure of a mobile terminal according to a first embodiment of the apparatus of the present invention; Figure 7 is a block diagram showing the structure of a mobile terminal according to a second embodiment of the present invention. Figure 8 is a block diagram showing a preferred structure of a mobile terminal according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention proposes an improved secure communication technique, in which the present invention provides an improved secure communication technique, in view of the problem of the inability of the related art to implement secure communication between mobile terminals. Using the public key of the receiving end to encrypt the shared key generated by the transmitting end to obtain the ciphertext, and preferably using the field with the network transparent transmission attribute to carry and transmit the ciphertext to the mobile terminal of the opposite end, when communicating after the call is established, The communication content can be encrypted and the corresponding decryption operation can be performed using the shared key, thereby enabling secure communication between the mobile terminals. It should be noted that, if not conflicting, the embodiments of the present invention and the various features in the embodiments may be combined with each other, and are all within the protection scope of the present invention. The embodiments of the present invention are described in the following with reference to the drawings, and the preferred embodiments described herein are intended to illustrate and explain the invention. It should be noted that the steps shown in the flowchart of the accompanying drawings may be performed in a computer system such as a set of computer executable instructions, and, although the logical order is shown in the flowchart, in some cases, The steps shown or described may be performed in an order different than that herein. Method Embodiment 1 According to this embodiment, a key transmission method based on mobile communication is provided. FIG. 1 is a flowchart of a key transmission method according to Embodiment 1 of the method of the present invention. As shown in FIG. 1, the key transmission method according to Embodiment 1 of the present invention includes the following steps S102 to S104. Step S102: The sending end generates a shared key, obtains a pre-stored public key of the receiving end, and encrypts the shared key by using the public key to obtain a ciphertext. Preferably, the sending end generates the shared key immediately after starting the call establishing process. Step S104: The sending end sends the ciphertext to the receiving end. Preferably, in order to enhance the security of the ciphertext delivery and save the system overhead, the sender can carry the ciphertext in the network with transparent transmission. (ie, the network does not do anything with the contents of the field) In the field of the attribute, a message including the field is sent to the receiving end. By means of the method provided in this embodiment, the shared key can be carried and transmitted through a field having a network transparent transmission attribute, so that the key can be easily and securely transmitted to the receiving end. The details of the above processing will be described in detail below.

(1) Step S102 The shared key mentioned in this embodiment may be one-time, that is, the shared key generated by the sender is different each time; thus, since the sender starts the call setup process, The shared key is generated, and the shared key is not stolen in advance; in addition, since the shared key is one-time, the key is not leaked due to repeated use of the same key, and the security of communication encryption can be improved. Preferably, for the public key of the pre-stored receiving end, it may be permanently transmitted by the receiving end to the transmitting end and stored locally at the transmitting end, or may be sent by the transmitting end before starting the call establishing process. Obtained from the receiving end and stored locally by a suitable method (for example, SMS mode, Bluetooth mode, etc.).

(2) Step S104 For the above-mentioned field having the network transparent transmission attribute, it may be a User-User Information Element (UUIE) field of a call setup message (ie, a SETUP message), which is easy to understand, UUIE here. A field is an instance of a field with properties that are transparent to the network. Of course, the present invention is not limited thereto, and may be carried in other fields having similar attributes according to the needs of implementation, including currently existing fields and fields that may appear in the future as the technology is improved. It is intended that the invention can be used without departing from the scope of the invention. As can be seen from the above description, in the related art, the process of key agreement is implemented by a complete communication process (for example, short message communication), and in this embodiment, after the call setup process is initiated by the sender The shared key is generated immediately, and the ciphertext is transmitted to the receiving end before the communication content is transmitted. Obviously, compared with the prior art, the present invention can undoubtedly save system overhead, and can save the user's communication cost from the user's point of view. . Method embodiment two The above describes the key transmission process. Based on the above key transmission process, the mobile terminal that is the opposite end of the transmitting end and the receiving end can implement the secure transmission of the mobile communication. Specifically, after the process of the key transmission is completed, preferably, the receiving end decrypts the received ciphertext by using a private key to obtain a shared key of the transmitting end; after the call is successfully established, the sending end uses the shared key. The communication content to be transmitted is encrypted, and the encrypted communication content is sent to the receiving end. At this time, the receiving end can decrypt the encrypted communication content by using the decrypted shared key to obtain communication that can be recognized by the user. content. In addition, the receiving end may further encrypt the communication content to be transmitted by using the shared key, and send the encrypted communication content to the transmitting end. Preferably, the public key and the private key of the receiving end are a pair of authenticated key pairs. In addition, it should be noted that the communication content mentioned herein may include, but is not limited to, data in the form of audio data, video data, and the like generated during communication. It can be seen that, compared with the related art, the communication content is encrypted by the encryption device, and the method provided by the embodiment is used to encrypt the communication content by software technology while communicating, which can save cost, is easy to use, and can be Improve the security of confidential communications. In the following, the mobile terminal carries the ciphertext in the UUIE field of the SETUP message as an example to describe the mobile communication secure transmission process according to the embodiment of the present invention, and FIG. 2 shows the signaling for performing the secure communication using the method shown in FIG. The process, as shown in FIG. 2, the secure transmission process can be implemented as follows: Step 202: The sender initiates a call setup process. (In a specific implementation process, after the sender user sends the number of the receiver user, it can be regarded as starting. Step 204, the sending end generates a shared key; Step 206, the sending end obtains the pre-stored public key of the receiving end locally; Step 208: The sending end encrypts the shared key by using the public key to generate The cipher text; Step 202 to Step 208 may correspond to the foregoing Step S102; Step 210, the transmitting end encodes the ciphertext, and writes the encoded ciphertext into the UUIE field of the SETUP message, and sets a flag bit in the field. To indicate that the UUIE field carries the ciphertext for the secure communication. In step 212, the sending end sends the SETUP message carrying the ciphertext to the receiving end. Step 21 0 to step 212 may correspond to the above step S104; Step 214: The sending end encrypts the communication content to be transmitted by using the shared key. Step 216: The sending end sends the encrypted communication content to the receiving end. Through the foregoing processing procedure, the sending end can transmit the shared key to the receiving end, and can encrypt the communication content by using the shared key, so that the transmission process is highly secure and saves system overhead. Described above is the processing of the transmitting end (i.e., the encryption process) in the secure communication, and the present invention is not limited thereto, and in the following embodiments, the processing of the receiving end (i.e., the decryption process) is described in detail. Method Embodiment 3 According to this embodiment, a mobile communication decryption method is provided. FIG. 3 is a flowchart showing a mobile communication decryption method according to Embodiment 3 of the method of the present invention, as shown in FIG.

As shown in FIG. 3, the mobile communication decryption method in the third embodiment of the method of the present invention includes the following steps S302 to S306. Step S302: The receiving end receives the message carrying the ciphertext from the sending end, and obtains the ciphertext carried in the field. Preferably, the ciphertext may be carried in a field with a network transparent transmission attribute of the message, for example, The messages used in the embodiments of the present invention may include, but are not limited to, a call setup message (SETUP message), and the fields used herein may include, but are not limited to, a UUIE field. Step S304, the receiving end decrypts the ciphertext by using its own private key to obtain a shared key generated by the transmitting end. Preferably, as described above, the private key and the public key used by the transmitting end to encrypt the shared key are used. A pair of authenticated key pairs; in step S306, the receiving end receives the encrypted communication content from the transmitting end (at the transmitting end, using the shared key to force the communication content. The specific method may refer to the foregoing method embodiment. b), and decrypt the encrypted communication content using the shared key to obtain the communication content. With the method provided in this embodiment, the receiving end can obtain the shared key provided by the sending end, and decrypt the received encrypted communication content by using the shared key to obtain the communication content identifiable by the user, thereby achieving confidentiality. Communication. The following describes the third embodiment of the method of the present invention by taking a SETUP message including a UUIE field as an example. FIG. 4 shows a signaling flow of a mobile communication decryption method according to a preferred embodiment of the present invention, such as As shown in FIG. 4, the process may be implemented in the following manner: Step 402: The receiving end receives the SETUP message from the sending end. Step 404: The receiving end parses the SETUP message. Step 406: The receiving end detects from the UUIE field of the SETUP message. Indicates that the cipher text is carried, and the ciphertext is obtained from the UUIE field according to the flag. Steps 402 to 406 may correspond to step S302. Step 408: The receiving end invokes its own private key pair ciphertext. Decrypting, obtaining a shared key generated by the sender, and saving the shared key; Step 408 may correspond to step S304 above; Step 410, after the call is successfully established, the receiving end receives the encrypted communication content from the sending end; 412. The receiving end decrypts the received encrypted communication content by using the shared key to obtain communication content that can be recognized by the user. Step 410 to step 412 may correspond to the foregoing step S306. Through the above processing, the receiving end may acquire the shared key from the field having the network transparent transmission attribute from the transmitting end, and decrypt the received encrypted communication content using the shared key to obtain the communication content. Method Embodiment 4 According to an embodiment of the present invention, a method for implementing secure communication is provided, including the following processing: First, a calling terminal generates a shared key A in a process of establishing a call with a called terminal, and shares the same. The key A is sent to the called terminal; wherein, after the calling terminal generates the shared key A in the process of establishing the call with the called terminal, the calling terminal performs the shared key A using the pre-saved public key K1. Encrypting and generating ciphertext B (encrypted shared key A), after encoding ciphertext B to a predetermined field of the predetermined message, transmitting the predetermined message to the called terminal through the network (corresponding to the key in the first embodiment of the method) For details of the transmission process, refer to the method embodiment 1 and no further details are provided herein. After the called terminal receives the predetermined message through the network, the called terminal decodes the ciphertext B from the predetermined field of the predetermined message; and decrypts the ciphertext B using the pre-saved private key K2 to obtain the shared key A. After the call is established, the calling terminal and the called terminal encrypt or decrypt the communication content using the shared key. That is to say, the sender can encrypt the communication content through the shared key, and send the encrypted communication content to the receiving end, the receiving end decrypts using the shared key, and the receiving end can also use the shared key to The communication content sent to the sender is encrypted, and the encrypted communication content is sent to the sender. After receiving the encrypted communication content, the sender decrypts it using the shared key. Through the above processing, the end-to-end security of the mobile terminal communication process can be effectively improved. Embodiment 1 of the device According to the embodiment, a mobile terminal is provided. Preferably, the mobile terminal provided in this embodiment can be used as a transmitting end in secure communication. And the key transmission method of the mobile communication provided in the first embodiment of the method is implemented by using the mobile terminal. FIG. 5 is a diagram showing the structure of a mobile terminal according to the first embodiment of the present invention. As shown in FIG. 5, the mobile terminal according to the first embodiment of the present invention includes a storage unit 1, a key generation unit 3, and a secret. The text generation unit 5, the construction unit 7, and the notification unit 9. The function of the above unit will be described in detail below. The storage unit 1 is configured to store a public key of the opposite mobile terminal; preferably, as above, the public key herein may be permanently authorized by the opposite mobile terminal as the receiving end to the mobile terminal as the transmitting end and stored locally at the transmitting end. The method may also be obtained from the receiving end and stored locally at the transmitting end by using multiple methods (for example, MMS mode, email mode, and Bluetooth mode) before the sending end initiates the call setup process. The key generation unit 3 is configured to generate a shared key. Preferably, the shared key may be generated immediately after the sending end initiates the call setup process. The ciphertext generating unit 5 is connected to the storage unit 1 and the key generating unit 3 for acquiring the public key from the storage unit 1, acquiring the shared key from the key generating unit 3, and using the public key to force the shared key The secret is obtained, and the ciphertext is obtained. Preferably, the above step S102 can be completed by using the storage unit 1, the key generation unit 3, and the ciphertext generation unit 5. Specifically, the shared key is first generated by the key generation unit 3, and then the ciphertext generation unit 5 acquires the public key of the peer mobile terminal stored in advance from the storage unit 1, and acquires the shared key from the key generation unit 3. And use the public key to encrypt the shared key to obtain the ciphertext. The construction unit 7 is connected to the ciphertext generation unit 5, and the ciphertext generated by the ciphertext generation unit 5 is carried in a field having a network transparent transmission attribute, and the field is carried in the message. The notification unit 9 is connected to the construction unit 7 for notifying the shared mobile terminal of the shared key by the message constructed by the construction unit 7. Preferably, the above-described step S104 can be completed using the construction unit 7 and the notification unit 9. Specifically, first, the constructing unit 7 acquires the ciphertext from the ciphertext generating unit 5, and carries the ciphertext in a field having a network transparent transmission attribute. Preferably, the field includes a UUIE field, and the field is carried in the message. Preferably, the message may be a SETUP message, and then the notification unit 9 obtains the above message from the construction unit 7, and sends the message to the opposite mobile terminal. With the mobile terminal provided by the embodiment, by setting a storage unit, a key generation unit, a ciphertext generation unit, a construction unit, and a notification unit, the shared key can be carried and transmitted through a field having a network transparent transmission attribute, thereby enabling Transfer the key easily and securely to the opposite end of the secure communication

(ie, the receiving end), and is highly secure and easy to implement. Based on the above description, FIG. 6 further shows a preferred structure of the mobile terminal according to the first embodiment of the apparatus according to the present invention. As shown in FIG. 6, the preferred structure of the mobile terminal according to the first embodiment of the apparatus according to the present invention includes: a unit 1, a key generation unit 3, a ciphertext generation unit 5, a construction unit 7, a notification unit 9, and an encryption unit 11 and a transmission unit 13, wherein the storage unit 1, the key generation unit 3, the ciphertext generation unit 5, The construction unit 7 and the notification unit 9 are similar in function to the corresponding units in FIG. 5, and are not described herein again. The functions of the compact unit 11 and the transmission unit 13 are described in detail below. The power density unit 11 is connected to the key generation unit 3 for encrypting the communication content to be transmitted using the shared key generated by the key generation unit 3; the sending unit 13 is connected to the encryption unit 11 for passing The communication content encrypted by the encryption unit 11 is sent to the opposite mobile terminal. By using the apparatus shown in FIG. 6, it is possible to generate a shared key at the transmitting end, encrypt the content of the secure communication, and transmit the key to the receiving end in a simple and secure manner, thereby realizing the transmitting end and the receiving end. Confidential communication between. Apparatus Embodiment 2 According to this embodiment, another mobile terminal is provided. Preferably, the mobile terminal provided in this embodiment can be used as a receiving end in the secure communication, and the mobile communication decryption method provided in the second embodiment of the foregoing method can be implemented by using the mobile terminal. FIG. 7 is a diagram showing the structure of a mobile terminal according to Embodiment 2 of the apparatus of the present invention, as shown in FIG. The mobile terminal according to the second embodiment of the present invention includes a first receiving unit 2, a parsing unit 4, and a first decrypting unit 6. The function of the above unit will be described in detail below. The first receiving unit 2 is configured to receive a message from the peer mobile terminal, where the field having the network transparent transmission attribute of the message carries the ciphertext, and the ciphertext is the peer mobile terminal that is the transmitting end, by using the local terminal as the receiving end The public key of the mobile terminal is obtained by encrypting the shared key; preferably, the first receiving unit 2 is used to complete the above step S302; the parsing unit 4 is connected to the first receiving unit 2 for receiving the first receiving unit 2 The message is parsed to get the ciphertext. The first decryption unit 6 is connected to the parsing unit 4 for decrypting the ciphertext using the stored private key of the mobile terminal to obtain a shared key. The above step S304 can be completed using the parsing unit 4 and the first decrypting unit 6. Specifically, the parsing unit 4 acquires a message from the first receiving unit 2, and parses the ciphertext from the message, and then the first decrypting unit 6 acquires the ciphertext from the parsing unit 4, and decrypts the ciphertext using its own private key. , get the shared secret. With the device provided in this embodiment, the shared key sent by the peer mobile terminal as the transmitting end can be parsed. FIG. 8 shows a preferred structure of a mobile terminal according to the second embodiment of the present invention. As shown in FIG. 8, the preferred structure of the mobile terminal according to the second embodiment of the present invention includes a first receiving unit 2 and a parsing unit 4. The first decryption unit 6, the second receiving unit 8, and the second decryption unit 10. The functions of the first unit, the parsing unit 4, and the first decrypting unit 6 are similar to those of the corresponding unit in FIG. 7, and are not mentioned here. The functions of the second receiving unit 8 and the second decrypting unit 10 will be described in detail below. a second receiving unit 8 configured to receive communication content from the opposite mobile terminal, where the communication content is encrypted at the opposite mobile terminal using a shared key; the second decryption unit 10 is connected to the second receiving unit 8 and the first The decryption unit 6 is configured to decrypt the communication content received by the second receiving unit 8 using the shared key obtained by the first decryption unit 6. Preferably, the above step S306 can be completed using the second receiving unit 8 and the second decrypting unit 10. Using the apparatus shown in FIG. 8, the receiving terminal can decrypt the received ciphertext to obtain a shared key, and decrypt the received confidential communication content using the shared key, thereby implementing secure communication. With the mobile terminal provided by the embodiment, by setting the second receiving unit and the decrypting unit, the shared key can be obtained from the field having the network transparent transmission attribute from the peer end of the secure communication (ie, the transmitting end), and the The shared key decrypts the encrypted communication content from the sender, and the communication content recognizable by the user can be obtained. As described above, with the technical solution of the present invention, the mobile terminal provided in Embodiment 1 of the foregoing apparatus is used at the transmitting end, and the mobile terminal provided by Embodiment 2 of the foregoing apparatus is used at the receiving end, and the method is used at the transmitting end. a method for transmitting a key of a mobile communication, using the mobile communication decryption method provided by the second embodiment of the method, that is, the sender uses the public key of the receiving end to encrypt the shared key generated by the sender to obtain the ciphertext, and The use of a field with network transparent transmission properties to carry and transmit ciphertext, and the use of a shared key to encrypt communication content enables secure communication between mobile terminals, and the encryption is highly secure, saves system overhead, is easy to use, and is easy to implement. Therefore, it is possible to solve the problem in the related art that the secure communication between the mobile terminals cannot be realized safely and simply, and the purpose of improving the degree of confidentiality can be achieved. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made therein are intended to be included within the scope of the present invention.

Claims

Claim

A key transmission method, comprising:

The sending end generates a shared key, obtains a pre-stored public key of the receiving end, and encrypts the shared key by using the public key to obtain a ciphertext;

The transmitting end carries the ciphertext in a message including a field having a network transparent transmission attribute, and sends the message to the receiving end.

2. The method according to claim 1, wherein the generating a shared key by the transmitting end comprises:

The sending end generates the shared key after starting the call setup process.

The method according to claim 1, wherein after the sending the message to the receiving end, the method further comprises:

The receiving end receives the message, obtains the ciphertext in the field included in the message, and decrypts the ciphertext by using the private key of the receiving end to obtain the shared key.

The method according to any one of claims 1 to 3, wherein, after the message is sent to the receiving end, the method further comprises:

After the call is successfully established, the transmitting end encrypts the communication content to be transmitted by using the shared key, and sends the encrypted communication content to the receiving end.

5. The method according to claim 4, further comprising:

The receiving end decrypts the received encrypted communication content using the shared key.

The method according to claim 5, further comprising:

The receiving end encrypts the communication content to be transmitted by using the shared key, and sends the encrypted communication content to the sending end.

The method according to claim 1, wherein the field having a network transparent transmission attribute comprises: a user information unit field in a call setup message.

8. A decryption method, comprising:

Receiving, by the receiving end, a message including a field having a network transparent transmission attribute from the transmitting end, and acquiring a ciphertext carried in the field, where the ciphertext is used by the sending end to use the public key pair of the receiving end to share the secret Generated by key encryption;

The receiving end decrypts the ciphertext by using its own private key to obtain the shared key generated by the sending end;

The receiving end receives the communication content encrypted by the shared key from the transmitting end, and decrypts the encrypted communication content by using the decrypted shared key to obtain a communication content.

9. The method according to claim 8, further comprising:

10. A method for implementing secure communication, comprising:

The calling terminal generates a shared key while performing call setup with the called terminal, and sends the shared key to the called terminal;

After the call setup is made, the calling terminal and the called terminal encrypt or decrypt the communication content using the shared key.

A mobile terminal, comprising:

a storage unit, configured to store a public key of the peer mobile terminal;

a key generation unit, configured to generate a shared key;

a ciphertext generating unit, configured to acquire the public key from the storage unit, obtain the shared key from the key generating unit, and encrypt the shared key by using the public key to obtain a secret Text

a constructing unit, configured to carry the ciphertext generated by the ciphertext generating unit in a field having a network transparent transmission attribute, and carry the field in a message;

a notification unit, configured to notify the peer mobile terminal of the shared key by using the message constructed by the constructing unit.

The mobile terminal according to claim 11, further comprising: an encryption unit, configured to encrypt the communication content to be transmitted by using the shared key; and a sending unit, configured to pass the encryption unit The encrypted communication content is sent to the opposite mobile terminal.

A mobile terminal, comprising:

a first receiving unit, configured to receive a message from the peer mobile terminal, where a field having a network transparent transmission attribute of the message carries a ciphertext, where the ciphertext is used by the mobile terminal by using the mobile terminal The public key of the terminal is obtained by encrypting the shared key;

a parsing unit, configured to parse the message received by the first receiving unit, to obtain the ciphertext; a first decrypting unit, configured to acquire, by using the stored private key of the mobile terminal, the parsing unit The ciphertext is decrypted to obtain the shared key.

The mobile terminal according to claim 13, further comprising:

a second receiving unit, configured to receive communication content from the peer mobile terminal, where the communication content is encrypted by the peer mobile terminal by using the shared key;

And a second decryption unit, configured to decrypt the communication content received by the second receiving unit by using the shared key obtained by the first decryption unit.