WO2009149579A1 - Secure communication method and apparatus based on ibe algorithm in the store and forward manner - Google Patents

Abstract

The technical solution of the present invention is that: the first user device used by the first user performs an encryption process based on the information to be sent for generating the encryption processed information, and sends the encryption processed information to the store and forward server; the second user device used by the second user receives the encryption processed information forwarded by the store and forward server from the first user device used by the first user, and performs a decryption process based on the received encryption processed information to revert to the original unencrypted information. The problem about being unable to support the end to end secure communication in the store and forward manner when establishing a secure communication in the communication network in the prior art can be solved through the solution.

Description

 IBE algorithm based on store-and-forward mode

 Method and device for secure communication

 The present invention relates to a method and apparatus for establishing secure communication in a communication network, and more particularly to a method and apparatus for establishing end-to-end secure communication in a store-and-forward mode based on an identity identification encryption algorithm. Background technique

 In the prior art, before establishing communication, a user must establish a secure channel with the communication partner to agree on what encryption algorithm to use and encryption and decryption keys, and in the subsequent communication process, according to the agreed encryption algorithm and encryption, The decryption key is used for encrypted communication to ensure the security of communication.

 In the prior art, a relatively mature scheme for establishing a secure channel encryption scheme, such as TLS (Transport Layer Security) and Kerberos, cannot solve the end-to-end security protection based on store-and-forward (ie, offline). problem.

 In order to establish a secure channel, both parties need to negotiate the relevant keys (such as session key, session key) and encryption algorithms. The session key can be generated by a random number or by a random number and a seed key, and sent out before the communication parties communicate. Once the session is interrupted, if either of the communicating parties is offline, these negotiated security information such as the session key will be invalid. The TLS mechanism and Kerberos currently only support the security protection of real-time online communication, and cannot solve the problem of communication data security protection of offline storage and forwarding systems.

 Specifically, for the TLS algorithm, in order to establish a secure channel, a mutual handshake, a negotiation encryption, a MAC (Message Authentication Code) algorithm, and a three-way handshake of a secret key based on one session of the communication session are required.

 Specifically, as shown in FIG. 1, the first handshake (H1), the user C sends a Client hello message to the server S; the second handshake H2, the server S sends a SeverHelloDone message to the user C for interacting with the user C, Serverhello, Certificate ,

1 EIE080032PCT ServerKeyExchange, CertificateRequest information; Third handshake H3, User C sends a Finished message to Server S, and simultaneously exchanges Certificate, ClientKeyExchange, and Certificate Verify information to establish a secure channel through 3 handshakes.

 Therefore, once any user is offline, the session is interrupted and the secure channel is interrupted.

 For the Kerberos algorithm, the session key is generated by the KDC (key distribution center). Therefore, the KDC knows the session key of all users. Once the information is leaked by the KDC, the information security of the user cannot be guaranteed. True end-to-end secure communication.

 In addition, in the existing application fields of secure communication, such as QQ and MSN shelK, we know that the traditional MSN messenger transmits messages in clear text, and the MSN shell adds the function of transmitting ciphertext information. Both support online message encryption algorithms. The MSN shell encrypts the message based on the RSA algorithm. However, the key and encryption algorithm negotiated by the two parties are valid only for the current online. Once the user goes offline and goes online again, the key and encryption algorithm negotiated by the user with the other party is no longer valid. Therefore, once a party is offline, the message transmission of the Chinese side can only be transmitted in clear text. Therefore, in the field of application of instant messaging for existing secure communication, there is no end-to-end (ie user-to-user) message. A mechanism for storing and forwarding secure communications.

 That is, the main disadvantages of the prior art are: The end-to-end secure communication with the offline user of the storage and forwarding system cannot be supported. Summary of the invention

 In view of the above problems in the prior art, the present invention provides a new solution, as follows: The first user equipment (sending device) used by the first user performs encryption processing based on information to be transmitted to generate an encrypted process. And transmitting, to the storage and forwarding server, the second user equipment (receiving device) used by the second user, receiving, by the first user, Encrypted processed information of a user equipment, based on received

2 EIE080032PCT The encrypted processed information is subjected to decryption processing to restore the original unencrypted processed information.

 According to a first aspect of the present invention, there is provided a second user equipment used by a first user of a communication network for performing identity-based encryption based on a second user equipment used by a second user offline by a store-and-forward server The method for secure communication includes the following steps: performing encryption processing based on information to be sent to generate encrypted processed information, and transmitting the encrypted processed information to the storage and forwarding server.

 According to a second aspect of the present invention, there is provided an identity-based encryption technology for a first user equipment used by a first user to be forwarded via a store-and-forward server in a second user equipment used by a second user of the communication network The method for decrypting the encrypted information, comprising the steps of: receiving encrypted processed information from the first user equipment used by the first user that is forwarded via the storage and forwarding server; The encrypted processed information is decrypted to restore the original unencrypted information.

 According to a third aspect of the present invention, there is provided a second user equipment used by a first user of a communication network for performing identity-based encryption technology with a second user equipment used by a second user offline by a store-and-forward server. a first encryption device for secure communication, comprising: a first sending device, configured to perform an encryption process based on information to be transmitted, to generate encrypted processed information, and send the encrypted processed information to the Store and forward server.

 According to a fourth aspect of the present invention, there is provided an identity-based encryption technology for a first user equipment used by a first user to be forwarded via a store-and-forward server in a second user equipment used by a second user of the communication network. The decrypting device for decrypting the encrypted information, comprising: receiving means, configured to receive the encrypted processed information from the first user equipment used by the first user and forwarded by the storage and forwarding server; decryption processing And means for performing decryption processing on the received encrypted information based on the received information to restore the original unencrypted processed information.

 Because of the private letter associated with the key used for decryption in the identity-based encryption algorithm

3 EIE080032PCT The information is generated by the private information generator based on the user's request, that is, the generation time of the private key is different from the generation time of the public key. Therefore, the first in the identity-based encryption algorithm system is not required before the secure channel is established. The first user equipment used by the user and the second user equipment used by the second user perform interaction with the security information related to establishing secure communication. Therefore, by adopting the technical solution provided by the present invention, the problem of offline secure communication is solved. DRAWINGS

 Other features, objects, and advantages of the present invention will become apparent from the Detailed Description of the Description.

 1 is a schematic diagram of a process in which a TLS algorithm in the prior art performs a three-way handshake between a user and a server for establishing a secure communication;

 2 is a schematic diagram of a topological structure of a communication network in accordance with an embodiment of the present invention;

 3 is a diagram of a user equipment 1 encrypting a CEK with a public key, encrypting information to be transmitted with a CEK, and transmitting the CEK encrypted by the public key and the CEK-encrypted information to the store-and-forward server, in accordance with an embodiment of the present invention. Method flow chart;

 4 is a flow chart of a method for decrypting information encrypted by an identity-based encryption technology from a user equipment 1 forwarded by a store-and-forward server in a user equipment 2, in accordance with an embodiment of the present invention;

 5 is a user equipment 1 encrypting a CEK with a public key, encrypting information to be transmitted with a CEK, and transmitting the CEK encrypted by the public key and the CEK-encrypted information to the store-and-forward server according to an embodiment of the present invention. Device block diagram;

 Figure 6 is a block diagram of an apparatus for decrypting information encrypted by an identity-based encryption technique from user equipment 1 forwarded via a store-and-forward server.

 In the figures, identical and similar reference numerals indicate the same or similar device or method steps.

4 EIE080032PCT detailed description

 Before explaining the specific embodiments in conjunction with the drawings, some of the concepts presented herein are first explained for understanding.

 Private Key Generator (PKG): The PKG includes a master secret for generating personal IBE private information. The PKG accepts the request message from the IBE system user to generate the IBE private information, and returns the IBE private information to the user after being authenticated by the user in an agreed manner. A PKG can have multiple users, each with a public identity that identifies itself.

 Public Parameter Server (PPS): Used to provide encrypted material that is shared publicly in the IBE (Identity-Based Encryption) system, including public parameters and PKG policy information.

 IBE system: A system that includes an identity-based encryption algorithm for a private information generator, a public parameter server, a transmitting device, a receiving device, and the like.

 Uniform Resource Identifier (URI): Every available resource on the Web. For example, HTML documents, images, video clips, programs, etc. are all passed by a generic resource identifier

 (Universal / Uniform Resource Identifier, referred to as "URI") for positioning.

 A URI is generally composed of three parts:

 - Access to the naming mechanism of the resource.

 - The host name where the resource is stored.

 - The name of the resource itself, represented by the path.

 User and User Equipment: A user can correspond to multiple user equipments. For example, if a user applies for a QQ account, the user can log in at home according to the QQ account, or log in at the Internet cafe. When logging in at home, the user device corresponding to the user is a home computer, and when logging in at the Internet cafe, The user equipment corresponding to the user is a computer of the Internet cafe. In the following description, the user A is the first user, and the corresponding user equipment is the user equipment 1 (ie, the first user equipment used by the first user); the user B is the second user, and the corresponding user equipment is the user equipment. 2 (ie the second user device used by the second user). In the following description, this correspondence is only an example, and those skilled in the art can understand that one user can correspond to multiple user equipments, that is, the following situations are used.

5 EIE080032PCT User A is the computer that is logged in to the computer with the MSN account. When user A logs in to the mobile phone with the same MSN account and uses the mobile MSN service, the corresponding user device is the mobile phone. User equipment includes computers, cell phones, PDAs, and the like.

 User identity related information: A user's user identity information is a globally unique ID or a unique ID in a closed domain. This ID is any unique string that directly represents the user's identity. It can be used by name, ID number, E. -mail address, SIM card number, mobile phone number (bind with user identity), device serial number, for example, the unique identifier of the computer used by the user (eg motherboard serial number, CPU serial number, etc., or a combination thereof), registered by the user at the server The username, for example, the MSN account, the QQ account, etc., or a combination thereof. According to the standard identity ID, the domain (such as country code, area code) and other identifiers (such as SIM card number, mobile phone number, etc.) of the user can be parsed.

 For example, the user A of the above is the ID of the user A, that is, the user A, when the user device used by the user A is a computer, a mobile phone or a PDA, or another user device logs in to the MSN service. MSN account number.

 CEK (Content Encryption Key) is a symmetric key that can be used to encrypt information to be sent. C EK encryption can be based on symmetric key algorithms such as DES (Data Encryption Standard) and AES (Advanced Encryption). .

 2 is a schematic illustration of a topology of a communication network in accordance with an embodiment of the present invention. The user equipment 1 (the first user equipment used by the first user) and the user equipment 2 (the second user equipment used by the second user) are two terminal user equipments that establish secure communication, which may be computer terminals or mobile phones. The application scenario of the terminal may be, for example, two end user devices using MSN or QQ chat software. When the peer-to-peer communication terminal of the user equipment 1, that is, the user equipment 2 is in an offline state (corresponding to two scenarios, i) the user equipment 2 is never logged in; ii) the user equipment 2 is originally online, due to network connection problems, etc. The reason is forced to go offline. The store-and-forward server 3 detects that the state of the user equipment 2 is offline (the person skilled in the art can understand that the store-and-forward server can be subdivided into a message communication server (MCS) and message and media storage. Server (Message and Media Storage, MMS),

6 EIE080032PCT MCS and MMS can be integrated in the same server, or they can be two separate servers. The MCS is mainly responsible for detecting the status of the user equipment, whether it is offline or online; and the MMS is mainly responsible for storing the encrypted ciphertext forwarded by the user equipment, and the storage and forwarding server 3 notifies the user equipment 1 that it is encrypted and sent to the user equipment 2. The processed information needs to be sent to the store-and-forward server, that is, the user device 1 transmits the encrypted processed information to the store-and-forward server 3 via the communication link 4. Those skilled in the art should understand that when the user equipment 1 is a computer, the user equipment 1 is connected to the router and connected to the access equipment (DSLAM), and finally logically connected to the store-and-forward server 3. When the user equipment 1 is a mobile phone user, the mobile phone user needs to perform wireless communication with the base station, and then finally communicate with the storage and forwarding server through a communication device such as a base station, and the communication link 4 is summarized. When the store-and-forward server 3 detects that the user equipment 2 is online, the store-and-forward server 3 forwards the encrypted processed information stored therein to the second user equipment 2 via the communication link 5. Similarly, in the following description, the link connection between the store-and-forward server 3 and the user equipment 2 is not expanded, but is summarized directly by the communication link 5.

 3 is a diagram of a user equipment 1 encrypting a CEK with a public key, encrypting information to be transmitted with a CEK, and transmitting the CEK encrypted by the public key and the CEK-encrypted information to the store-and-forward server, in accordance with an embodiment of the present invention. Method flow chart.

 In step S10, the user equipment 1 acquires the unified resource identifier of the public parameter server of the user B. Since the identity related information of User B is well known, the identity related information includes location identification information. For example, when user B is a mobile phone user and the identity related information is a phone number, the identity related information of the user B includes location identification information.

 (+86), according to the location identification information indicated by the identity related information, the IBE system may query the uniform resource identifier of the public parameter server corresponding to the user B.

 Then, in step S11, the user equipment 1 locates the public parameter server by using the uniform resource identifier of the public parameter server.

 In step S12, the user equipment 1 performs mutual authentication with the public parameter server of the located user B.

7 EIE080032PCT Specifically, the authentication of the user equipment 1 and the public parameter server may adopt a universal authentication method based on the network access authentication and the key agreement mechanism, that is, GBA (Generic).

Bootstrapping Authentication ) ( 3 GPP TS 33.220 ) , the authentication process between the user equipment 1 and the public parameter server can be as follows: After receiving the public parameter request message from the user equipment 1 , the public parameter server checks whether there is a user A (using the user of User Equipment 1) corresponds to a valid pre-shared key (pre-shared key is a Unicode string), if there is no pre-shared key, the GBA process is initiated, the process is: BSF (bootstrap service) Function, Bootstrapping Server Function ) (Assume that the BSF and the public parameter server are combined into one physical device) Check whether there is a valid 5-way authentication vector (Authentication Vector) corresponding to User A (user using User Device 1). RAND, CK, IK, AUTN, RES) or triple authentication vector (including: RAND Kc, RES). Among them, CK (Cipher Key) and Kc are mainly used for encryption and IK (Integrity Key) is mainly used for integrity check. If the BSF has a 5-tuple or triplet authentication vector corresponding to User A, a set of authentication vectors is selected therefrom; if not, the BSF will obtain an authentication vector from the HSS (Home Subscriber Server) (please refer to 3GPP TS33 based) .220, 3GPP TS 33.102, 3GPP TS 33.103 and 3GPP TS 33.105 Diameter and MAP protocol), HSS will generate a 5-tuple or triplet authentication vector according to the capability of the terminal (User A), and then return to the BSF, where, The tuple authentication vector contains communication device authentication information (for example, RAND, RES), management device authentication information (for example, RAND, AUTN), and a security policy known by UE1 (for example, CK). Then the BSF and the user equipment 1 generate the pre-shared key in the same way (ie, the user equipment 1 derives the pre-shared key by IK, CK and other parameters in the same way as the BSF), and the BSF forwards the pre-shared key to Public parameter server. User A and the public parameter server authenticate based on the pre-shared key using an associated authentication mechanism (such as HTTP Digest, PSK-TLS, etc.).

 In addition, mutual authentication between user A and the public parameter server may also be based on PKIJBC or HTTP digest.

 Then in step S13, the user equipment 1 obtains the public parameters of the user B from the authenticated public parameter server. Common parameters include elliptical algorithm curve identification, prime number, prime number,

8 EIE080032PCT Common base point, encrypted hash function, etc.

 Then, proceeding to step S14, the user equipment 1 generates the public key of the user B according to the public parameters of the user B and the identity related information of the user B. The specific algorithm for generating User B's public key is related to the ietf organization (see http:〃 www.ietf.org/rfc/rfc5091 ixt, http://www.ietf.org/internet-drafts/draft-ietf-smime The relevant provisions in -bfibecms-08.txt, http://www.ietf.org/internet-drafts/draft-ietf-smime-ibearch-06.txt) are not described here.

 Then, proceeding to step S15, the user equipment 1 encrypts the information to be sent by using the encrypted auxiliary information to generate information encrypted by the encrypted auxiliary information, and encrypts the encrypted auxiliary information with the obtained public key of the user B to generate a public information. The encrypted auxiliary information after the key is encrypted, and the encrypted information encrypted by the encrypted auxiliary information and the encrypted auxiliary information encrypted by the public key are sent to the storage and forwarding server.

 Specifically, step S15 may be refined into the following sub-steps (not shown in FIG. 3): In step α, the user equipment 1 generates the encryption assistance information randomly generated according to the local (for example, CEK, Content Encryption Key, content encryption key). The information to be sent is encrypted to generate CEK-encrypted information. Among them, different lengths of CE can be selected according to the length of the encryption algorithm.

 In step β, the user equipment 1 transmits the CEK-encrypted information to the store-and-forward server.

 In step i, the user equipment 1 encrypts the CEK with the user's public key to generate a CEK encrypted by the user B public key.

 In step ii, the user equipment 1 transmits the CEK encrypted by the user B public key to the storage and forwarding server 3.

 Through the above description, those skilled in the art can understand that the step β takes the step α, the step ii takes the step 1, and in a modified embodiment, the step α can be performed first, then the step i is performed, and then the step β is performed. Step ii is further performed; preferably, step β and step ii can be performed simultaneously, that is, the CEK-encrypted information and the public key-encrypted CEK are simultaneously sent to the store-and-forward server 3.

 In the above embodiment, the user equipment 1 adds the CEK using the public key of the user B.

9 EIE080032PCT Confidential, the information to be sent by the CEK is encrypted. Considering that the CEK is based on a symmetric key encryption algorithm (such as the AES algorithm), encrypting the information to be sent by the CEK can save the time required for encryption. An asymmetric cryptosystem approach (such as a public-private key pair algorithm) requires a large amount of computation and is not suitable for encrypting large amounts of information. The CEK itself has less information, so the CEK is encrypted with the public key in the asymmetric cryptosystem. Encrypting the information to be sent with CEK can also improve the efficiency as a whole, but because of the introduction of a new parameter CEK, it may bring Come to the complexity of the system. Thus, without considering the system cost, we can also directly encrypt the information to be sent by the public key in the asymmetric cryptosystem, that is, in a variant embodiment, the user equipment 1 directly uses the asymmetric cipher. The public key in the system encrypts the information to be sent. Then step S 15 can be subdivided into the following sub-steps (shown in Figure 3):

 Step S150: The user equipment 1 encrypts the information to be sent by using the acquired public key of the user B to generate information encrypted by the public key of the user B.

 Then, proceeding to step S151, the user equipment 1 transmits the information encrypted by the public key of the user B to the store-and-forward server.

 In the above embodiment, after mutual authentication between user A and user B's public parameter server is successful, it can be considered that user A and user B's public parameter server are mutually trusted. However, the user A accesses the public parameter server of the user B in the local area network through the VPN (Virtual Private Network), because the user A and the local area network are connected securely, at this time, the user A does not need to perform the interaction with the user B. Mutual authentication, that is, in a modified embodiment, the step of mutual authentication by the user equipment 1 of step S12 and the public parameter server of the located user B may be omitted, then in step S13, the user equipment 1 is directly Get the public parameters of User B from the public parameter server.

 In another modified embodiment, steps S10, S1, and S12 may be omitted, that is, corresponding to such a scenario, the user equipment 1 has previously established secure communication with the user B, and thus the user is stored in the user equipment 1. The information of the public parameter server corresponding to B, therefore, the user equipment 1 directly obtains the public parameters of the user B according to the information of the public parameter server corresponding to the user B stored therein.

10 EIE080032PCT In another variant embodiment, steps S10, Sl1, S12 and S13 may each be omitted. That is, corresponding to such a scenario, the user equipment 1 has previously established secure communication with the user B, so the public parameter corresponding to the user B is stored in the user equipment 1, and the life cycle of the public parameter is not expired, and is still valid information. Therefore, in step S14, the user equipment 1 directly obtains the public key of the user B according to the public parameters of the user B and the identity related information of the user B.

 In another modified embodiment, before step S15, the step of acquiring the encryption auxiliary information may be locally generated CEK information, or may be obtained from the outside, but for obtaining the situation from the outside, The security performance is not high, therefore, preferably, the auxiliary information is randomly generated from the local. It is to be noted that the acquisition step of the encryption auxiliary information is only required to be performed before the step of encrypting the information to be transmitted by using the CEK.

 Hereinafter, with reference to FIG. 4, a flowchart of a method for decrypting information encrypted by the identity-based encryption technology from the user equipment 1 forwarded by the store-and-forward server in the user equipment 2 of the present invention will be specifically described with reference to FIG.

 Before the store-and-forward server forwards the user device 1 to the user device 2, the store-and-forward server first detects whether the user device 2 is online. If the store-and-forward server detects that the user device 2 is online, it will store the data from the store-and-forward server. The information encrypted by the user equipment 1 of the user equipment 1 is forwarded to the user equipment 2. We understand that existing offline messages are also forwarded via the server.

 First, the case where the information transmitted by the user equipment 1 to the store-and-forward server is encrypted by the encrypted auxiliary information and the encrypted auxiliary information encrypted by the public key is described as follows:

 In step S20, the user B receives the encrypted auxiliary information from the user equipment 1 used by the user A, which is forwarded via the store-and-forward server. The following uses the encrypted auxiliary information as the CEK as an example. The encrypted information and the public key are used. Encrypted auxiliary information after encryption.

 Specifically, there is no obvious sequence between the sub-steps of the user equipment 2 acquiring the CEK-encrypted information and the sub-steps of acquiring the CEK encrypted by the user B's public key.

11 EIE080032PCT That is, the store-and-forward server can simultaneously transmit the CEK-encrypted information and the CEK encrypted by the user B's public key to the user equipment 2, or can transmit the two separately. However, the CEK can only be decrypted after the user equipment 2 receives the CEK encrypted by the user B's public key. Only after the user equipment 2 obtains the decrypted CEK can the received CEK encrypted information be decrypted.

 After the user equipment 2 receives the CEK encrypted by the user B and the public key forwarded via the store-and-forward server, the user equipment 2 parses the public parameter server of the user B from the packet header of the information in step S21. URI, and locating the public parameter server of the user B according to the URI of the public parameter server of the user B, the user B and the public parameter server of the user B are mutually authenticated. For the specific authentication step, refer to step S12 of FIG. 3 above. User A and the public parameter server authentication process. It should be understood by those skilled in the art that the authentication mechanism may be a general authentication method based on network access authentication and key agreement mechanism, GBA, PKI, 基于-based algorithm or HTTP digest, etc., and will not be described herein.

 Then in step S22, the user equipment 2 acquires the public parameters of the user B from the public parameter servers of the mutually authenticated user B. User B's public parameters include the ellipse algorithm curve identifier, prime number, prime number, common base point, encrypted hash function, and so on.

 In addition, the public parameter server of the user B also includes the policy information of the PKG, that is, in step S23, the user device 2 can obtain the URL of the user B's PKG from the public parameter server by interacting with the public parameter server.

 In step S24, the user equipment 2 locates the private information generator by using the uniform resource identifier of the private information generator.

 In step S25, the user equipment 2 and the private information generator perform mutual authentication. In general, since the private information of User B held by the private information generator is critical to the secure communication of User B, mutual authentication between the User Equipment 2 and the Private Information Generator PKG is required. For the mutual authentication process, the specific steps may refer to the authentication process of the user A and the public parameter server for step S12 in FIG. 3 above. Those skilled in the art should understand that the authentication mechanism may be a universal authentication method based on network access authentication and key agreement mechanism, GBA, PKI, 基于-based algorithm or

12 EIE080032PCT HTTP digest and so on, will not be described here.

 In step S26, the user equipment 2 acquires the private information of the user B from the mutually authenticated private information generator. Because the private information relates to the security of the user B, once the private information is leaked, it will cause immeasurable loss to the user B. Therefore, the private information should be transmitted to the user equipment 2 in a secure manner. For example, the encryption mechanism includes PKI, ΙΒΕ, and the like.

 In the system, private information is generated by the private information generator PKG and provided to the decrypted user. Is it necessary to generate a new private key for the session depending on whether the encrypted user uses a long-term public key or a short-term? Public key. This decision is influenced by system security policies and customer policies that enforce encryption.

 PKG needs to maintain a database to store each private ID corresponding to the current system parameter configuration. A key can be generated, used, revoked or removed after the end of its life cycle.

 In step S27, the user equipment 2 generates the private key of the user B according to the acquired public parameters of the user B, the private information of the user B, and the identity related information of the user B. The user B's private key is also based on the IBE algorithm. The specific algorithm for generating the user B's private key is related to the ietf organization (see http://www.ietf.org/rfc/rfc5091.txt http://wwwJetf. There are provisions in org/internet-drafts/draft-ietf-smime-bfibecms-Q8.txt, http://wwwjetf.org/internet-drafts/draft-ietf-smime-ibearch-06.txt ) Do not repeat them.

 In step S28, the user equipment 2 decrypts the received CEK encrypted by the user B's public key using the private key of the user B to restore the CEK.

 In step S29, the user equipment 2 decrypts the received CEK-encrypted information with the restored CEK to restore the original information.

 In the above embodiment, in step S21, the user equipment 2 needs to rely on the steps.

The encrypted message obtained in S20 parses out the URI of User B's public parameter server. However, in a variant embodiment, the user equipment 2 can communicate directly with the IBE system to obtain the URI of the public parameter server corresponding to the user B, and further locate the public parameter server based on the URI of the obtained public parameter server. That is,

13 EIE080032PCT At this time, there is no obvious sequence in step S20 and step S21. However, only the user equipment 2 completes the CEK-encrypted information of the user equipment 1 used by the user A forwarded via the store-and-forward server at the reception of step S20 and The CEK encrypted by the public key also acquires the private key of the user B in step S27, and then proceeds to step S28, and uses the private key of the user B to decrypt the private key encrypted by the public key of the user B, Restore unencrypted CEK.

 In another variant embodiment, steps S21, S22 can all be omitted. That is, corresponding to such a scenario, the user equipment 2 has previously authenticated with the public parameter server, and the authentication has not expired, so step S21 can be omitted; and the user equipment 2 has acquired the user B from the public parameter server. The corresponding public parameter stores the public parameter corresponding to the user B in the user equipment 1, and the life cycle of the public parameter does not expire, and is still valid information. Therefore, step S22 can be omitted. Then, in step S23, the user equipment 2 directly obtains the uniform resource identifier of the private information generator from the public parameter server that has been mutually authenticated.

 In a variant embodiment, steps S23, S24, S25, S26 may be omitted. Although the private information generator periodically updates the user's identity information with the corresponding private information, but the life cycle of a private message continues for a period of time. time. That is, there is a case where the user B has obtained the private information of the user B from the private information generator the previous time, and the private information has not expired, and is still valid. Therefore, in step S27, the user equipment 2 directly generates the private key of the user B according to the private information of the user B stored locally, the identity related information of the user B, and the public parameter of the user B stored locally.

 In a variant embodiment, if the information to be sent in the user equipment 1 is encrypted, the information to be sent is directly encrypted using the public key of the user B, and the encrypted information forwarded to the store-and-forward server is used. Correspondingly, the ciphertext encrypted by the public key of the user B, correspondingly, step S28 and step S29 may be replaced with step S28, and the user equipment 2 encrypts the received information encrypted by the public key of the user B by using the private key of the user B. Decryption is performed to restore the original unencrypted information, that is, the information to be sent by the user A.

14 EIE080032PCT 5 is a user equipment 1 encrypting a CEK with a public key, encrypting the information to be transmitted with the CEK, and transmitting the public key encrypted CEK and the CEK encrypted information to the store and forward server according to an embodiment of the present invention. Device block diagram.

 Hereinafter, various specific embodiments of the third aspect of the present invention will be described with reference to FIG. 5 in conjunction with FIG. 2, wherein the description of FIG. 3 is hereby incorporated by reference. The first encryption device 10 shown in FIG. 5 is located in each terminal device of the user equipment 1 shown in FIG. 1 , and includes a server identifier acquisition device 100, a server location device 101, and a first public parameter acquisition device 102. The key obtaining device 103 and the first transmitting device 104; wherein the first common parameter obtaining device 102 further includes a first server authentication device 1020 and a second common parameter obtaining device 1021.

 First, the server identification obtaining means 100 acquires the uniform resource identifier of the public parameter server of the user B. Since the identity related information of User B is well known, the identity related information includes location identification information. For example, when the user B is a mobile phone user and the identity related information is a phone number, the identity related information of the user B includes location identification information (+86), and the IBE system can query according to the location identification information indicated by the identity related information. The uniform resource identifier of the public parameter server corresponding to the user B.

 The server locating device 101 locates the common resource identifier of the public parameter server acquired in the device 100 by the server, and locates the public parameter server.

 The first server authentication device 1020 performs mutual authentication with the public parameter server of the located user B.

 Specifically, the authentication of the first server authentication device 1020 and the public parameter server may adopt a universal authentication method based on the network access authentication and the key agreement mechanism, that is, GBA (Generic Bootstrapping Authentication) (3GPP TS 33.220), the first server authentication. The key agreement process between the device 1020 and the public parameter server may be as follows: After receiving the public parameter request message from the first server authentication device 102, the public parameter server checks whether it has a user Α (using the user device 1) User) corresponding to the valid pre-shared key, if there is no pre-shared key, start the GBA process, the process is: BSF (Bootstrapping Server Function) (assuming BSF and public parameter server are set to one physical device) to see if they are User A (using user equipment

15 EIE080032PCT The user of 1) corresponds to a valid five-factor authentication vector (including: RAND, CK, IK, AUTN, RES) or a triplet authentication vector (including: RAND, Kc, RES). Among them, CK (Cipher Key) and Kc are mainly used for encryption and IK (Integrity Key) is mainly used for integrity check. If the BSF has a 5-tuple or triplet authentication vector corresponding to User A, a set of authentication vectors is selected therefrom; if not, the BSF will obtain an authentication vector from the HSS (Home Subscriber Server) (please refer to 3GPP TS33 based) .220, 3 GPP TS 33.102, 3GPP TS 33.103 and 3GPP TS 33.105 Diameter and MAP protocol), HSS will be able to generate a quintuple or triplet authentication vector and then return it to the BSF, where The quintuple authentication vector contains communication device authentication information (for example, RAND, RES), management device authentication information (for example, RAND, AUTN), and a security policy known by UE1 (for example, CK). The BSF then generates a pre-shared key in the same manner as the first server authentication device 1020, and the BSF forwards the pre-shared key to the public parameter server. The first server authentication device 1020 and the public parameter server perform authentication based on the pre-shared key using an associated authentication mechanism (such as HTTP Digest PSK-TLS).

 In addition, mutual authentication between user A and the public parameter server may also be based on PKI, IBC or HTTP digest.

 The second public parameter obtaining means 1021 then acquires the public parameters of the user B from the authenticated public parameter server. Common parameters include elliptical algorithm curve identification, prime numbers, prime numbers, common base points, encrypted hash functions, and more.

 The public key obtaining means 103 then generates the public key of the user B based on the public parameters of the user B and the identity related information of the user B. The specific algorithm for generating User B's public key is related to the ietf organization (see http:〃 www.ietf.org/rfc/rfc5091.txt,

Http://wwwjetf.org/internet-drafts/draft-ietf-smime-bfibecms-08.txt, http://wwwJetf.org/internet-drafts/draft-ietf-smime-ibearch-06.txt ) The relevant regulations are not described here.

 Then, the first transmitting device 104 encrypts the information to be transmitted by using the encrypted auxiliary information to generate the encrypted information of the encrypted auxiliary information, and encrypts the encrypted auxiliary information with the acquired public key of the user B to generate a public key encrypted. Encrypted auxiliary letter

16 EIE080032PCT Information, and the encrypted information encrypted by the encrypted auxiliary information and the encrypted auxiliary information encrypted by the public key are sent to the store-and-forward server.

 Specifically, the first transmitting device 104 can be refined into the following sub-devices (not shown in FIG. 5):

 a third encryption device, based on locally generated encrypted auxiliary information (for example, CEK

Content Encryption Key, the information to be sent is encrypted to generate CEK-encrypted information. Among them, different lengths of CEK can be selected according to the length of the encryption algorithm.

 The CEK-encrypted information transmitting apparatus, the user equipment 1 transmits the CEK-encrypted information to the store-and-forward server.

 The fourth encryption device, the user equipment 1 encrypts the CEK with the public key of the user B to generate a CEK: encrypted by the user B public key.

 The information transmitting apparatus encrypted by the public key transmits the CEK encrypted by the user B public key to the store-and-forward server 3.

 Through the above description, those skilled in the art can understand that the content transmitted by the CEK-encrypted information transmitting apparatus must be generated by the third encrypting apparatus, and the content transmitted by the public key-encrypted information transmitting apparatus must be transmitted by the fourth encrypting apparatus. However, there is no obvious sequence between the steps performed by the third encryption means and the CEK-encrypted information transmitting means and the steps performed by the fourth encryption means and the public key-encrypted information transmitting means. Preferably, the CEK-encrypted information transmitting device and the public key-encrypted information transmitting device may be combined into one second transmitting device, that is, the second transmitting device simultaneously encrypts the CEK-encrypted information and the public-key encrypted CEK. Send to the store-and-forward server 3.

 In the above embodiment, the user equipment 1 encrypts the CEK with the user B public key, and encrypts the information to be sent by the CEK, considering that the CEK is based on a symmetric key encryption algorithm (such as the AES algorithm), so the CEK is used to be sent. Encryption of information can save time in encryption. An asymmetric cryptosystem approach (such as a public-private keying algorithm) requires a large amount of computation and is not suitable for encrypting large amounts of information. The CEK itself has less information, so the CEK is encrypted with the public key in the asymmetric cryptosystem.

17 EIE080032PCT The CEK encryption of the information to be sent as a whole can also improve efficiency, but because of the introduction of a new parameter CEK, the complexity of the system may be brought about. Thus, without considering the system cost, we can also directly encrypt the information to be sent by the public key in the asymmetric cryptosystem, that is, in a variant embodiment, the user equipment 1 directly uses the asymmetric cipher. The public key in the system encrypts the information to be sent. Then, the first transmitting device 104 can be subdivided into the following sub-devices (shown in FIG. 5):

 The second encrypting means encrypts the information to be transmitted by using the acquired public key of the user to generate the information encrypted by the user's public key.

 The second transmitting device transmits the information encrypted by the user's public key to the storage forwarding server.

 In the above embodiment, after the mutual authentication between the user and the public parameter server of the user B is successful, it can be considered that the user A and the public parameter server of the user B are mutually trusted. However, the user A accesses the public parameter server of the user B in the local area network through the VPN (Virtual Private Network), because the user A and the local area network are connected securely, at this time, the user A does not need to perform the interaction with the user B. Mutual authentication, that is, in a variant embodiment, the first server authentication device 102 can be omitted, and the first common parameter acquisition device (not shown) directly obtains the public parameters of the user B from the public parameter server.

 In another variant embodiment, the server identification obtaining device 100, the server positioning device 101, and the first server authentication device 1020 may all be omitted, that is, corresponding to such a scenario, the user device 1 previously established secure communication with the user B. Therefore, the information of the public parameter server corresponding to the user B is stored in the user equipment 1. Therefore, the first public parameter obtaining means 102 directly acquires the public parameters of the user B according to the information of the public parameter server corresponding to the user B stored therein.

 In another variant embodiment, the server identification obtaining means 100, the server positioning means 101, the first server means 1020 and the second common parameter server 1021 may each be omitted. That is, corresponding to such a scenario, the user equipment 1 has previously established a secure communication with the user B, so the public parameter corresponding to the user B is stored in the user equipment 1, and the life cycle of the public parameter has not expired, and is still valid information. Therefore, public

18 EIE080032PCT The key obtaining means 103 directly acquires the public key of the user B according to the public parameter of the user B and the identity related information of the user B.

 In another variant embodiment, the first encryption device 10 further includes an encryption auxiliary information acquisition device, which may be locally generated CEK information, or may be externally acquired, but is secure for externally obtaining such a situation. The performance is not high, therefore, preferably, the auxiliary information is randomly generated from the local. Then, the third encryption device encrypts the information to be sent according to the acquired CEK.

 Hereinafter, with reference to FIG. 6, in conjunction with FIG. 2 and FIG. 4, a block diagram of a device for decrypting information encrypted by the identity-based encryption technology from the user equipment 1 forwarded by the storage and forwarding server in the user equipment 2 of the present invention is specifically described. description.

 Hereinafter, various specific embodiments of the fourth aspect of the present invention will be described with reference to FIG. 6 in conjunction with FIG. 2, wherein the description of FIG. 4 is hereby incorporated by reference. The decryption device 20 shown in FIG. 6 is located in each terminal device exemplified by the user equipment 2 shown in FIG. 1, and includes a receiving device 200, a second server authentication device 201, a third public parameter obtaining device 202, and a generator identifier. The obtaining device 203, the generator locating device 204, the first private information obtaining device 205, the private key obtaining device 206, and the decrypting processing device 207; wherein the first private information obtaining device 205 further includes a generator authentication device 2050 and second private information. The acquisition device 2051; the decryption processing device 207 further includes an auxiliary information decryption device 2070 and an original information decryption device 2071.

 Before the store-and-forward server forwards the user device 1 to the user device 2, the store-and-forward server first detects whether the user device 2 is online. If the store-and-forward server detects that the user device 2 is online, it will store the data from the store-and-forward server. The information encrypted by the user equipment 1 of the user equipment 1 is forwarded to the user equipment 2. We understand that existing offline messages are also forwarded via the server.

 First, the information that the information sent by the user equipment 1 to the store-and-forward server is encrypted by the encrypted auxiliary information, and the encrypted auxiliary information encrypted by the public key is described as follows:

 First, the receiving device 200 receives the encrypted auxiliary information from the user equipment 1 used by the user A, which is forwarded via the store-and-forward server, and the following is the encrypted auxiliary information.

19 EIE080032PCT For the CEK as an example, the encrypted information and the encrypted auxiliary information encrypted by the public key are described.

 Specifically, there is no obvious sequence between the sub-step of acquiring the CEK-encrypted information performed by the receiving device 200 and the sub-step of acquiring the CEK encrypted by the user B's public key, that is, the store-and-forward server can simultaneously The CEK-encrypted information and the CEK encrypted by the user B's public key are simultaneously transmitted to the user equipment 2, and the two can also be transmitted separately. However, the CEK can only be decrypted after the user equipment 2 receives the CEK encrypted by the user B's public key. The received CEK-encrypted information can only be decrypted after the user equipment 2 has obtained the decrypted CEK.

 After the receiving device 200 receives the CEK encrypted by the user B and the public key forwarded via the store-and-forward server, the second server authentication device 201 receives the information packet header of the CEK encrypted by the public key of the user B. The URI of the public parameter server of the user B is parsed, and the public parameter server of the user B is located according to the URI of the public parameter server of the user B. Then, the user B and the public parameter server of the user B perform mutual authentication, and the specific authentication step may be performed. Refer to the authentication process of the user A and the public parameter server for step S12 of FIG. 3 described above. It should be understood by those skilled in the art that the mechanism for the authentication may be a universal authentication method based on network access authentication and key agreement mechanism, GBA, PKI, 基于-based algorithm or HTTP digest, etc., and will not be further described herein.

 The third public parameter obtaining means 202 then acquires the public parameters of the user B from the public parameter server of the mutually authenticated user B. User B's public parameters include the ellipse algorithm curve identifier, prime number, prime number, common base point, encrypted hash function, and so on.

 In addition, the public parameter server of the user B also includes the policy information of the PKG, that is, the generator identifier obtaining means 203 can obtain the URL of the user B's PKG from the public parameter server by interacting with the public parameter server.

 Then, the generator identification locating device 204 user equipment 2 locates the private information generator through the uniform resource identifier of the private information generator.

 Then, the generator authentication device 2050 performs mutual authentication with the private information generator. Usually, because the privacy information of user B saved by the private information generator is used

20 EIE080032PCT The secure communication of the subscriber B is essential, and therefore mutual authentication between the generator authentication device 2050 and the private information generator PKG is required. For the process of mutual authentication, the specific steps may refer to the authentication process of the user A and the public parameter server for step S12 in FIG. 3 above. It should be understood by those skilled in the art that the mechanism of the authentication may be a general authentication mode GBA, PKI, an IBE based algorithm, or an HTTP digest based on a network access authentication and a key agreement mechanism, and the like, and details are not described herein.

 Then, the second private information obtaining means 2051 acquires the private information of the user B from the mutually authenticated private information generator. Since the private information relates to the security of the user B, once the private information is leaked, it will cause immeasurable loss to the user B. Therefore, the private information should be transmitted to the user equipment 2 in a secure manner, for example, the encryption mechanism is PKL IBE.

 In the IBE system, private information is generated by the private information generator PKG and provided to the decrypted user. Is it necessary to generate a new private key for the session depending on whether the encrypted user uses a long-term public key or a short-term? Public key. This decision is influenced by system security policies and customer policies that enforce encryption.

 PKG needs to maintain a database to store each private ID corresponding to the current system parameter configuration. A key can be generated, used, revoked or removed after the end of its life cycle.

 Then, the private key obtaining means 206 generates the private key of the user B based on the acquired public parameters of the user B, the private information of the user B, and the identity related information of the user B. The user B's private key is also based on the IBE algorithm. The specific algorithm for generating the user B's private key is related to the ietf organization (see http://www.ietf.org/rfc/rfc5Q91.txt, http://wwwjetf). .org/intemet-drafts/draft-ietf-smime-bfibecms-08.txt, http:〃 www.ietf.org/interne1:-drafts/draft-ietf-smime-ibearch-06.txt ) , I will not repeat them here.

 Then, the auxiliary information decrypting means 2070 decrypts the received CEK encrypted by the user B's public key using the private key of the user B to restore the CEK.

 Finally, the original information decryption means 2071 decrypts the received CEK-encrypted information with the restored CEK to restore the original information.

21 EIE080032PCT In the above embodiment, the second server authentication apparatus 201 needs to resolve the URI of the public parameter server of the user B depending on the encrypted message acquired in the receiving apparatus 200. However, in a variant embodiment, the decryption device 20 can communicate directly with the IBE system to obtain the URI of the public parameter server corresponding to the user B, and further locate the public parameter server based on the URI of the acquired public parameter server. That is, there is no obvious sequence between the steps performed by the receiving device 200 and the second server authentication device 201 at this time, but only the receiving from the receiving device 200 is completed and the user A is forwarded via the store-and-forward server. The CEK encrypted information of the user equipment 1 and the CEK encrypted by the public key, the private key obtaining means 206 also acquires the private key of the user B, and the decryption processing means 207 can use the private key of the user B for the user B. The public key encrypted CEK decrypts the private key to restore the unencrypted CEK.

 In another variant embodiment, both the second server authentication device 201 and the third public parameter acquisition device 202 may be omitted. That is, corresponding to such a scenario, the decryption device 20 has previously authenticated with the public parameter server, and the authentication has not expired, so the second server authentication device 201 can be omitted; and the decryption device 20 has been from the public parameter server. The public parameter corresponding to the user B is obtained, and the public parameter corresponding to the user B is stored in the user equipment 1, and the life cycle of the public parameter is not expired, and is still valid information. Therefore, the third public parameter obtaining device 202 can omit . Then, the generator identification obtaining means 203 directly obtains the uniform resource identifier of the private information generator from the public parameter server that has been mutually authenticated.

 In a variant embodiment, generator identifier acquisition means 203, generator location means 204, generator authentication means 2050 and second private information acquisition means 2051 may be omitted. Although the private information generator periodically updates the private information associated with the user's identity information, the life cycle of a private message lasts for a while. That is, there is a case where the user B has obtained the private information of the user B from the private information generator the previous time, and the private information has not expired, and is still valid. Therefore, the private key obtaining means 206 directly generates the private key of the user B according to the private information of the user B stored locally, the identity related information of the user B, and the public parameters of the locally stored user B.

22 EIE080032PCT In a modified embodiment, if the information to be sent in the user equipment 1 is encrypted, the information to be sent directly by the public key of the user B is encrypted, and the encrypted information forwarded to the storage and forwarding server is used. User B's public key encrypted ciphertext, correspondingly, auxiliary information decryption device 2070 and original information decryption device 2071 may be replaced with decryption processing device 207, and decryption processing device 207 uses user B's private key for the received user The information encrypted by B's public key is decrypted to restore the original unencrypted information, that is, the information to be sent by user A.

 The embodiments of the present invention have been described above, but the present invention is not limited to the specific systems, equipment, and specific protocols, and various modifications and changes can be made by those skilled in the art within the scope of the appended claims.

23 EIE080032PCT

Claims

Claim A method for performing secure communication based on identity encryption technology in a first user equipment used by a first user of a communication network by a second user equipment used by a second user of the offline by a store-and-forward server, wherein The following steps:  C. Performing an encryption process based on the information to be transmitted to generate the encrypted processed information, and transmitting the encrypted processed information to the store-and-forward server.  The method according to claim 1, wherein the step c comprises: cl. encrypting the information to be sent by using the obtained public key of the second user to generate a solution The information after the public key is encrypted;  C2. Send the public key encrypted information to the store-and-forward server. The method according to claim 1, wherein the step c further comprises the following steps:  - Obtain encrypted auxiliary information;  The step C further includes:  And encrypting the information to be sent by using the obtained encryption auxiliary information to generate information encrypted by the encrypted auxiliary information, and using the obtained public key of the second user to obtain the encryption auxiliary The information is encrypted to generate encrypted auxiliary information encrypted by the public key, and the encrypted information encrypted by the encrypted auxiliary information and the encrypted auxiliary information encrypted by the public key are sent to the storage and forwarding server.  The method according to claim 2 or 3, wherein before the step c, the method further comprises:  a. Obtain public parameters from the public parameter server;  Obtaining, according to the public parameter and the identity related information of the second user, the public key of the second user.  The method according to claim 4, wherein before the step a, the method further comprises:  - obtaining a uniform resource identifier of the public parameter server;  - locating the public parameter by using a uniform resource identifier of the public parameter server 24 EIE080032PCT server;  The step a further includes: obtaining a public parameter from the located public parameter server.  The method according to claim 4 or 5, wherein the step a further comprises the following steps:  Al. mutual authentication with the public parameter server;  A2. Acquire the public parameters of the second user from the mutually authenticated public parameter server.  The method according to any one of claims 4 to 6, wherein the identity related information of the second user comprises an ID of the second user.  The method according to any one of claims 4 to 7, wherein the common parameters include an elliptical algorithm curve identifier, a prime number, a prime number, a common base point, and an encrypted hash function.  9. A method for decrypting information encrypted by an identity-based encryption technology of a first user device used by a first user forwarded via a store-and-forward server in a second user device used by a second user of the communication network , including the following steps C. receiving encrypted processed information from the first user device forwarded via the store-and-forward server;  D. Perform decryption processing based on the received encrypted processed information to restore original unencrypted processed information.  The method according to claim 9, wherein the step D further comprises: privately receiving the public key encrypted information that has been received by using the acquired private key of the second user Key decryption to restore the original unencrypted information.  The method according to claim 9, wherein the step C further comprises: receiving encrypted encrypted auxiliary information from the first user equipment used by the first user, which is forwarded by the storage and forwarding server, after being encrypted Information and encrypted auxiliary information encrypted by public key;  The step D further includes the following steps: 25 EIE080032PCT Dl. Using the obtained private key of the second user, performing private key decryption on the received encrypted auxiliary information encrypted by the public key to restore unencrypted encrypted auxiliary information;  D2. Decrypt the received information encrypted by the encrypted auxiliary information by using the restored unencrypted encryption auxiliary information to restore the original unencrypted information.  12. The method according to claim 10 or 11, wherein before the step D, the following steps are further included:  A. Obtain public parameters from the public parameter server;  B. Acquiring the private key of the second user according to the obtained public parameter, the acquired private information of the second user, and the identity related information of the second user.  13. The method according to claim 12, wherein the step A further comprises the following steps:  - mutual authentication with the public parameter server;  The step A further includes: acquiring a public parameter of the second user from a public parameter server that has been mutually authenticated.  The method according to claim 12 or 13, wherein after the step A, the step B further comprises the following steps:  I. Obtain the private information of the second user from the private information generator.  The method according to claim 14, wherein after the step A, the step I further comprises the following steps:  - obtaining a uniform resource identifier of the private information generator from the public parameter server;  - locating the private information generator by using a uniform resource identifier of the private information generator;  The step I further includes: obtaining the private information of the second user from the located private information generator.  16. The method according to claim 14, wherein the step I further comprises the following steps:  - mutual authentication with the private information generator; 26 EIE080032PCT - obtaining private information of the second user from the private information generator that has been mutually authenticated.  The method according to any one of claims 12 to 16, wherein the identity related information of the second user comprises an ID of the second user.  The method according to any one of claims 12 to 17, wherein the common parameters include an elliptical algorithm curve identifier, a prime number, a prime number, a common base point, and an encrypted hash function.  19. A first encryption device for performing secure communication based on identity encryption technology in a first user device used by a first user of a communication network for use by a second user device used by a second user offline by a store-and-forward server, Among them, including:  And a first sending device, configured to perform an encryption process based on the information to be sent, to generate the encrypted processed information, and send the encrypted processed information to the storage forwarding server.  The first encryption device according to claim 19, wherein the first transmitting device further comprises:  a second encryption device, configured to encrypt the information to be sent by using the acquired public key of the second user, to generate information encrypted by the public key;  The second transmitting device sends the public key encrypted information to the storage forwarding server.  The first encryption device according to claim 19, further comprising:  An auxiliary information obtaining device, configured to obtain encrypted auxiliary information;  The first sending device is further configured to: encrypt the information to be sent by using the obtained encrypted auxiliary information, to generate information encrypted by the encrypted auxiliary information, and use the acquired second The public key of the user encrypts the encrypted auxiliary information to generate encrypted auxiliary information encrypted by the public key, and the encrypted information encrypted by the encrypted auxiliary information and the encrypted auxiliary encrypted by the public key Information is sent to the store-and-forward server.  22. The first encryption device according to claim 20 or 21, wherein 27 EIE080032PCT Also includes:  a first public parameter obtaining device, configured to obtain a public parameter from a public parameter server;  The public key obtaining means is configured to acquire the public key of the second user according to the public parameter and the identity related information of the second user.  The first encryption device according to claim 22, further comprising:  a server identifier obtaining device, configured to acquire a unified resource identifier of the public parameter server;  a server positioning device, configured to locate the public parameter server by using a uniform resource identifier of the public parameter server;  The first public parameter obtaining apparatus is further configured to acquire a public parameter from the located public parameter server.  The first encryption device according to claim 22 or 23, wherein the first common parameter acquisition device further comprises:  a first server authentication device, configured to perform mutual authentication with the public parameter server;  And a second common parameter obtaining means, configured to acquire the common parameter of the second user from the mutually authenticated public parameter server.  The first encryption device according to any one of claims 22 to 24, wherein the identity related information of the second user comprises an ID of the second user.  The first encryption apparatus according to any one of claims 22 to 25, wherein the common parameters include an elliptical algorithm curve identifier, a prime number, a prime number, a common base point, and an encrypted hash function.  27. Decryption of a second user device used by a second user of a communication network for decrypting information encrypted by an identity-based encryption technology of a first user device used by a first user forwarded via a store-and-forward server The device, comprising: receiving means, configured to receive encrypted processed information from a first user equipment used by the first user, which is forwarded by the storage and forwarding server; 28 EIE080032PCT The decryption processing means is configured to perform decryption processing based on the received encrypted processed information to restore the original unencrypted processed information.  The decryption device according to claim 27, wherein the decryption processing device is further configured to: encrypt the received public key by using the obtained private key of the second user The information is decrypted by the private key to restore the original unencrypted information.  The decrypting apparatus according to claim 27, wherein the receiving apparatus is further configured to: receive encrypted auxiliary information from the first user equipment used by the first user, which is forwarded via the storage and forwarding server The encrypted information and the encrypted auxiliary information encrypted by the public key;  The decryption processing device further includes:  The auxiliary information decrypting device is configured to decrypt the encrypted public auxiliary key encrypted by the public key with the acquired private key of the second user to restore the encrypted auxiliary information without being encrypted. ;  The original information decryption means is configured to decrypt the received information encrypted by the encrypted auxiliary information by using the restored unencrypted encryption auxiliary information to restore the original unencrypted information.  The decryption device according to claim 28 or 29, further comprising:  a third public parameter obtaining device, configured to obtain a public parameter from a public parameter server;  The private key obtaining means is configured to obtain the private key of the second user according to the acquired public parameter, the acquired private information of the second user, and the identity related information of the second user.  The decryption device according to claim 30, further comprising:  a second server authentication device, configured to perform mutual authentication with the public parameter server;  The third public parameter obtaining apparatus is further configured to acquire the public parameter of the second user from a public parameter server that has been mutually authenticated.  The decryption device according to claim 30 or 31, further comprising: 29 EIE080032PCT The first private information obtaining device acquires the private information of the second user from the private information generator.  The decryption device according to claim 32, further comprising: a generator identifier obtaining means, configured to obtain a uniform resource identifier of the private information generator from the public parameter server;  a generator locating device, configured to locate the private information generator by using a uniform resource identifier of the private information generator;  The first private information obtaining apparatus is further configured to obtain the private information of the second user from the located private information generator.  The decryption device according to claim 32, wherein the first private information obtaining device further comprises:  a generator authentication device, configured to perform mutual authentication with the private information generator; and a second private information obtaining device, configured to acquire private information of the second user from the mutually authenticated private information generator.  The decryption apparatus according to any one of claims 30 to 34, wherein the identity related information of the second user includes an ID of the second user.  The decryption apparatus according to any one of claims 30 to 35, wherein the common parameters include an elliptical algorithm curve identifier, a prime number, a prime number, a common base point, and an encrypted hash function.  37. A first user equipment for use by a first user of a communication network for secure communication based on identity encryption technology with a second user equipment used by a second user of an offline forwarding and forwarding server, characterized in that it comprises A first encryption apparatus for performing secure communication based on identity encryption technology via a store-and-forward server with a second user device used by an offline second user, according to any one of claims 19 to 26.  38. A second user equipment for use by a second user of a communication network for decrypting information encrypted by an identity-based encryption technology of a first user device used by a first user, forwarded via a store-and-forward server, A decryption apparatus for decrypting information encrypted by an identity-based encryption technology from a first user device used by a first user, which is forwarded via a store-and-forward server, according to any one of claims 27 to 36.  30 EIE080032PCT