Group device identity authentication and key negotiation method and system for mobile edge computing environment based on distributed learning

Abstract

The application provides a group device identity authentication and key negotiation method and system for a mobile edge computing environment based on distributed learning, and relates to the technical field of information security. The method comprises an initialization stage, a registration stage, an authentication and key negotiation stage; wherein in the authentication and key negotiation stage, the terminal device selects a temporary public key and signs it, generates a request message and sends it to the mobile edge server to complete authentication of itself; the mobile edge server authenticates the request message of the terminal device collected and, after the authentication is passed, selects a temporary key to sign the identity of the terminal device and sends it to the cloud server to apply for a group identity; the cloud server returns an encrypted group identity after verifying the signature; the mobile edge server decrypts the group identity to obtain a group session key and sends it to the terminal device to complete the response; the terminal device generates a group session key after receiving the response message to complete key confirmation.

Description

Technical Field

[0001] The present invention relates to the field of information security technology, and in particular to a method and system for group device identity authentication and key negotiation in a mobile edge computing environment based on distributed learning. Background Art

[0002] Distributed learning (DL) is an emerging machine learning paradigm that enables users to jointly train models without sharing training data, thereby resolving data silos and protecting user privacy. Combining DL technology with mobile edge computing can more effectively leverage the distributed nature of both and improve data utilization efficiency. In a DL-based mobile edge computing environment, the system model consists of terminal devices, cloud servers, and mobile edge servers. Terminal devices, such as vehicles and mobile phones, are primarily used to collect data; cloud servers primarily coordinate the system and do not directly access raw data, but instead update and integrate learning models; mobile edge servers are used to coordinate and coordinate joint learning and data sharing among terminal devices. Terminal devices collaborate to complete model training without sharing raw data with each other.

[0003] To ensure secure communication between devices in group communication scenarios within DL-based mobile edge computing environments, authentication schemes and key agreement schemes (AKA) have been proposed in recent research. These schemes should not only securely complete mutual authentication and session key establishment, but also be highly efficient. However, while most existing lightweight authentication and key agreement mechanisms can also be applied to mobile edge computing and provide asymmetric encryption security mechanisms, they have high computational costs, leading to numerous security issues. Traditional identity authentication and key agreement protocols are not suitable for DL-based mobile edge computing environments. Traditional encryption methods and protocols are subject to specific constraints in the perception layer. Because smart terminal devices in mobile edge computing environments generally have weak storage and computing capabilities and cannot handle large amounts of data processing and computation, further requirements are placed on the authentication protocol during identity authentication and the key agreement protocol after authentication. Summary of the Invention

[0004] In response to the problems of high computational cost and poor security of existing device authentication and key agreement schemes in DL-based mobile edge computing environments, the present invention provides a method and system for group device identity authentication and key agreement in a mobile edge computing environment based on distributed learning.

[0005] On the one hand, the present invention provides a method for group device identity authentication and key negotiation in a mobile edge computing environment based on distributed learning, including: an initialization phase, a registration phase, an authentication and key negotiation phase;

[0006] During the initialization phase, the trusted center generates and publishes system parameters;

[0007] In the registration phase, the terminal device and the mobile edge server use system parameters to complete the registration at the trusted center to obtain their respective long-term private keys and identities during the communication process;

[0008] During the authentication and key negotiation phase, the terminal device generates a temporary public key and signs the temporary public key using system parameters, its own long-term private key and identity, generates a request message and sends it to the mobile edge server to complete its own authentication; the mobile edge server authenticates the request message collected from the terminal device and, after the authentication is passed, selects a temporary key and signs the identity of the terminal device using the temporary key, system parameters and its own long-term private key and sends it to the cloud server to apply for a group identity from the cloud server; after the cloud server successfully verifies the signature, it returns the encrypted group identity to the mobile edge server; after the mobile edge server decrypts the group identity, it calculates the group session key and sends it to the terminal device to complete the response; after receiving the response message from the mobile edge server, the terminal device generates the group session key and completes the key confirmation.

[0009] Furthermore, the trusted center generates and publishes system parameters, specifically including:

[0010] The trusted center selects the cyclic point group G on the elliptic curve, sets the group generator P∈G, the order to q, and the security parameter to λ; selects the one-way hash functions h1, h2, h3, h4, h5; and randomly selects the system master private key. And calculate the corresponding public key P pub =sP; publish system parameters {P,q,h1,h2,h3,h4,h5,P pub}.

[0011] Furthermore, the terminal device and the mobile edge server complete registration at the trusted center using system parameters to obtain their respective long-term private keys and identities during communication, specifically including:

[0012] The terminal device or mobile edge server randomly selects an integer locally The intermediate parameter X = xP is calculated and {RID, X} is sent to the trusted center. RID is the real identity of the terminal device or mobile edge server.

[0013] The trusted center verifies whether the RID is in the user list and within the registration validity period. If it is not in the user list or the registration information has expired, it randomly selects an integer for the terminal device or mobile edge server. And perform the following operations on the terminal device or mobile edge server: If it is a terminal device, encrypt the RID of the terminal device with the system master private key to generate the pseudonym PID of the terminal device, and calculate the intermediate parameters R = rP and y = r + sh1 (PID, R), and reply {PID, R, y} to the terminal device through a secure channel; If it is a mobile edge server, directly calculate the intermediate parameter R = rP, and directly use the RID of the mobile edge server to calculate y = r + sh1 (RID, R), and reply {RID, R, y} to the mobile edge server through a secure channel;

[0014] After receiving the response from the secure channel, the terminal device or mobile edge server verifies the equation yP=R+h1(ID,R)P pub Is it true? If so, store it safely.<x,y> As its own long-term private key; wherein, ID is the pseudonymous PID of the terminal device or the RID of the mobile edge server.

[0015] Furthermore, the terminal device generates a temporary public key and signs the temporary public key using system parameters, its own long-term private key and identity identifier, and sends the signature to the mobile edge server, specifically including:

[0016] Terminal Equipment (ED) i Randomly select an integer As a temporary private key, and calculate the temporary public key Then calculate the intermediate parameter k i,1 and k i,2 : in, Indicates terminal equipment ED i T i is a timestamp string, state2 is a message identification string corresponding to the group communication message, Indicates terminal equipment ED i The long-term public key; then calculate the intermediate parameters Finally generate the signature The signature and signature related information form a request message Sent to the mobile edge server MEC j ;in, Indicates terminal equipment ED i The long-term private key of Represents the Mobile Edge Server MEC j The long-term public key.

[0017] Furthermore, the mobile edge server authenticates the collected request message from the terminal device, specifically including:

[0018] Mobile Edge Server (MEC) j Collect the request messages received from n terminal devices within the time interval δ and calculate To complete the identity authentication of the terminal device; and Represents the mobile edge server MEC j Temporary public key and long-term private key, For terminal equipment ED i The long-term public key, T j1 For timestamp strings, P and P pub These are all system parameters.

[0019] Furthermore, the selecting of a temporary key and using the temporary key, system parameters and its own long-term private key to sign the identity of the terminal device and send it to the cloud server specifically includes:

[0020] Mobile Edge Server (MEC) j choose As a temporary private key, and calculate the temporary public key Then calculate the intermediate parameter k j,1 and k j,2 : Among them, T j1 For timestamp string; then calculate the intermediate parameters Indicates the terminal device MEC j The long-term private key finally generates the request message Send to the cloud server.

[0021] 7. The method for group device identity authentication and key agreement in a distributed learning-based mobile edge computing environment according to claim 1, wherein the cloud server returns an encrypted group identity to the mobile edge server after successfully verifying the signature, specifically comprising:

[0022] After receiving the signature, the cloud server verifies the signature and generates a group identity for the group if the verification passes. <GID j ,VT j > Among them, GID j is the identification string, VT jis a timestamp string, and the group identity is identified by the session key between the mobile edge server and the cloud server. <GID j ,VT j > After encryption, it is sent to the mobile edge server MEC j .

[0023] Furthermore, after the mobile edge server decrypts and obtains the group identity, it calculates the group session key and sends it to the terminal device to complete the response, which specifically includes:

[0024] Mobile Edge Server (MEC) j After receiving the message from the cloud server, the session key between the mobile edge server and the cloud server is used to decrypt the message to obtain the group identity. <GID j ,VT j >; Calculate the intermediate parameter k first e,1 and k e,2 : Among them, T j2 For timestamp string; then calculate the intermediate parameters Then calculate the group session key And generate the signature C of the group session key according to the following process j :

[0025] The signature and signature related information form the response information Sent to terminal device ED i Completion response; PGID j and η are intermediate parameters, P is a system parameter, Indicates the identity of the mobile edge server.

[0026] Furthermore, the terminal device generates a group session key after receiving a response message from the mobile edge server, and completes key confirmation, specifically including:

[0027] Terminal Equipment (ED) i After receiving the response message from the mobile edge server, calculate Then generate the group session key And verify the equation Is it true? If so, store the group session key gsk securely. i , and start communication within the group.

[0028] On the other hand, the present invention provides a group device identity authentication and key agreement system in a mobile edge computing environment based on distributed learning, comprising: a trusted center, a terminal device, a mobile edge server, and a cloud server;

[0029] The trusted center is used to generate and publish system parameters during the initialization phase. During the registration phase, it is used for terminal devices and mobile edge servers to complete registration with the trusted center using the system parameters to obtain their respective long-term private keys and identities during communication.

[0030] The terminal device is configured to select a temporary public key during the authentication and key negotiation phase, sign the temporary public key using system parameters, its own long-term private key, and its identity, generate a request message, and send it to the mobile edge server to complete its own authentication; and generate a group session key upon receiving a response message from the mobile edge server to complete key confirmation;

[0031] During the authentication and key negotiation phase, the mobile edge server is used to authenticate the collected request messages from the terminal devices. After authentication, the mobile edge server selects a temporary key and signs the terminal device's identity using the temporary key, system parameters, and its own long-term private key. The signature is then sent to the cloud server to request a group identity from the cloud server. The mobile edge server is also used to decrypt the obtained group identity, calculate the group session key, and send it to the terminal device to complete the response.

[0032] The cloud server, in the authentication and key agreement phase, is used to verify the signature successfully and return the encrypted group identity to the mobile edge server.

[0033] Beneficial effects of the present invention:

[0034] In a mobile edge computing environment based on distributed learning, the certificateless group device identity authentication and key negotiation protocol for a mobile edge computing environment based on distributed learning of the present invention can resist man-in-the-middle attacks, spoofing attacks, session key leakage attacks, long-term private key leakage attacks, temporary key leakage attacks, etc., effectively improving the security of data interaction in a mobile edge computing environment based on distributed learning, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A flow chart of a method for group device identity authentication and key agreement in a mobile edge computing environment based on distributed learning provided by an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of the process of terminal device registration provided in an embodiment of the present invention;

[0037] Figure 3 A schematic diagram of the process of authentication and key negotiation between a terminal device, a mobile edge server, and a cloud server provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] like Figure 1 As shown, an embodiment of the present invention provides a method for group device identity authentication and key negotiation in a mobile edge computing environment based on distributed learning, which includes three stages: protocol initialization, protocol participant registration, and authentication and key negotiation.

[0040] During the initialization phase, the trusted center (TA) generates and publishes system parameters, which mainly include the system master key and a secure hash function.

[0041] In the registration phase, the terminal device and the mobile edge server use system parameters to complete the registration at the trusted center to obtain their respective long-term private keys and identities during the communication process;

[0042] Specifically, during the registration phase, the terminal device generates its own user-side long-term private key and sends it together with its real identity to the trusted center through a secure channel. After receiving the registration application, the trusted center generates a pseudonym and another part of the long-term private key for the terminal device. Finally, the terminal device securely stores the two long-term private keys after completing verification.

[0043] The registration process for a mobile edge server differs slightly from that for a terminal device. In an MEC environment, the mobile edge server, as part of the service provider, does not need to hide its identity. Therefore, during registration, the server uses its real identity instead of generating a pseudonym. After registration, the mobile edge server also possesses its own long-term private key.

[0044] During the authentication and key negotiation phase, the terminal device selects a temporary public key and signs the temporary public key using system parameters, its own long-term private key, and an identity identifier, and generates a request message and sends it to the mobile edge server to complete its own authentication; the mobile edge server authenticates the request message collected from the terminal device and, after the authentication is passed, selects a temporary key and signs the identity identifier of the terminal device using the temporary key, system parameters, and its own long-term private key and sends it to the cloud server to apply for a group identity identifier from the cloud server; after the cloud server successfully verifies the signature, it returns the encrypted group identity identifier to the mobile edge server; after the mobile edge server decrypts the group identity identifier, it calculates the group session key and sends it to the terminal device to complete the response; after receiving the response message from the mobile edge server, the terminal device generates a group session key and completes the key confirmation.

[0045] The identity authentication and key negotiation method provided by the embodiment of the present invention realizes session key negotiation of group terminal devices, can resist man-in-the-middle attacks, spoofing attacks, session key leakage attacks, long-term private key leakage attacks, temporary key leakage attacks, etc., effectively improves the security and reliability of group communication in a mobile edge computing environment based on distributed learning, and has good application prospects.

[0046] In one embodiment, the initialization phase of the trusted center TA is as follows:

[0047] First, the TA selects a suitable cyclic point group G on the elliptic curve, assuming that the group generator is P (an element in group G), the order is q (a large prime number), and the security parameter is λ; then the TA selects five secure one-way hash functions h1, h2, h3, h4, and h5, where each hash function is defined as h1: h2: h3: h4:G→{0,1} * 、h5:{0,1} * ×G→{0,1} * ; Then TA randomly selects the system master private key s (group ), and calculate the corresponding system master public key P pub =sP(element in group G); finally TA announces the system parameters {P,q,h1,h2,h3,h4,h5,P pub}.

[0048] Based on the above embodiments, the terminal device ED i and Mobile Edge Computing Server MEC jAll need to register with the trusted center TA to obtain a long-term public key / private key. In addition, since the data uploaded by the terminal device to the server may contain some private information, in addition to the long-term public key / private key, a pseudonym will be assigned to the terminal device. Assume that the TA is completely reliable and the entire registration phase is completed in a secure channel. In one embodiment, Figure 2 As shown, taking the terminal device as an example, for the identity identifier RID EDi ED i For example, it will obtain a long-term private key and pseudonym during the registration phase. The specific registration process is as follows: i First, complete the selection of the user's partial private key locally, randomly select and calculate Once the selection is complete it will Send to TA. TA first checks Is it in the user list and within the registration validity period? If it is not in the list or the registration information has expired, it is ED i Random selection And complete the operation: TA response Give ED i ED i After receiving the response from the secure channel, verify the equation Is it true? If verification is completed, it is stored securely. And disclose the terminal device ED i The long-term public key

[0049] For the identity Mobile Edge Server MEC j For example, it will obtain a long-term private key during the registration phase. The specific registration process is as follows: MEC j First, complete the selection of the user's partial private key locally, randomly select and calculate Once the selection is complete it will Send to TA. TA first checks Is it in the user list and within the registration validity period? If it is not in the list or the registration information has expired, it is MEC j Random selection And complete the operation: TA response Give MEC j MEC j After receiving the response from the secure channel, verify the equation Is it true? If verification is completed, it is stored securely. And open the mobile edge server MEC j The long-term public key

[0050] In one embodiment, Figure 3 As shown, during the authentication and key agreement phase, the terminal device, mobile edge server, and cloud server implement the following computational steps:

[0051] ED i Random selection As a temporary private key and sign: After the calculation is completed, ED i The request message Send to MEC j ; where k i,1 、k i,2 and s i All groups The elements in T i is a timestamp string, and state2 is a message identification string, indicating that the message is a group communication message.

[0052] MEC j Collect the request messages received from n terminal devices within the time interval δ and calculate (in, is an element in group G, s i ′ is a group Elements in in For terminal equipment ED i to complete the identity authentication of the requesting terminal device.

[0053] Next, MEC j choose And sign the pseudonym for the terminal device application: k j,1 、k j,2 and s j All groups The elements in T j1 is a timestamp string; and sends To the cloud server.

[0054] After receiving the signature, the cloud server verifies the signature and generates a group ID for the group if the verification passes. <GID j ,VT j >(where GID j is the identification string, VT j is a timestamp string), and the session key SK between the mobile edge computing server and the cloud server j,cloud Encrypted and sent to MECj .

[0055] MEC j After receiving the message, use the session key to decrypt and obtain <GID j ,VT j > Union operation: Among them, T j2 is a timestamp string; calculate the group session key:

[0056] Last sent Give ED i Complete response; k e,1 、k e,2 、s e and All groups The elements in PGID j and η are both intermediate parameters;

[0057] ED i After receiving the request response message, perform the following operations: in, is an element in group G, For the group Elements in (group ), and verify the equality Is it true? If so, store the group session key gsk securely. i , and start communication within the group.

[0058] In a mobile edge computing environment based on distributed learning, the certificateless group device identity authentication and key agreement protocol for a mobile edge computing environment based on distributed learning in the embodiment of the present invention can resist man-in-the-middle attacks, impersonation attacks, session key leakage attacks, long-term private key leakage attacks, temporary key leakage attacks, etc., effectively improving the security of data interaction in a mobile edge computing environment based on distributed learning, and has good application prospects.

[0059] The embodiment of the present invention also provides a group device identity authentication and key agreement system in a mobile edge computing environment based on distributed learning, including a trusted center, a terminal device, a mobile edge server and a cloud server;

[0060] During the initialization phase, the trusted center generates and publishes system parameters. During the registration phase, the terminal device and mobile edge server register with the trusted center using the system parameters to obtain their respective long-term private keys and identities for communication. During the authentication and key agreement phase, the terminal device selects a temporary public key, signs the temporary public key using the system parameters, its own long-term private key, and its identity, and generates a request message to send to the mobile edge server to authenticate itself. Upon receiving a response message from the mobile edge server, the terminal device generates a group session key and completes key confirmation. During the authentication and key agreement phase, the mobile edge server authenticates the collected terminal device request message. Once authentication is successful, the mobile edge server selects a temporary key and signs the terminal device's identity using the temporary key, system parameters, and its own long-term private key. The signature is then sent to the cloud server to request a group identity. After decrypting the obtained group identity, the mobile edge server calculates the group session key and sends it to the terminal device to complete the response. During the authentication and key agreement phase, the cloud server verifies the signature and returns the encrypted group identity to the mobile edge server.

[0061] It should be noted that the system provided in the embodiment of the present invention is for implementing the above method. Its specific functions can be referred to the above method embodiments and will not be described in detail here.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for group device identity authentication and key agreement in a mobile edge computing environment based on distributed learning, characterized in that: include: Initialization phase, registration phase, authentication and key negotiation phase; During the initialization phase, the trusted center generates and publishes system parameters, including: the trusted center selects the cyclic point group G on the elliptic curve, sets the group generator P∈G, the order to q, and the security parameter to λ; selects the one-way hash functions h1, h2, h3, h4, and h5; and randomly selects the system master private key. And calculate the corresponding public key P pub =sP; publish system parameters {P,q,h1,h2,h3,h4,h5,P pub }; In the registration phase, the terminal device and the mobile edge server use the system parameters to complete the registration at the trusted center to obtain their respective long-term private keys and identities during the communication process. Specifically, the terminal device or the mobile edge server randomly selects an integer locally. The intermediate parameter X = xP is calculated and {RID, X} is sent to the trusted center. RID is the real identity of the terminal device or mobile edge server. The trusted center verifies whether the RID is in the user list and within the registration validity period. If it is not in the user list or the registration information has expired, it randomly selects an integer for the terminal device or mobile edge server. And perform the following operations on the terminal device or mobile edge server: If it is a terminal device, encrypt the RID of the terminal device with the system master private key to generate the pseudonym PID of the terminal device, and calculate the intermediate parameters R = rP and y = r + sh1 (PID, R), and reply {PID, R, y} to the terminal device through a secure channel; If it is a mobile edge server, directly calculate the intermediate parameter R = rP, and directly use the RID of the mobile edge server to calculate y = r + sh1 (RID, R), and reply {RID, R, y} to the mobile edge server through a secure channel; After receiving the response from the secure channel, the terminal device or mobile edge server verifies the equation yP=R+h1(ID,R)P pub Is it true? If so, store it safely.<x,y> As its own long-term private key; where ID is the pseudonymous PID of the terminal device or the RID of the mobile edge server; During the authentication and key negotiation phase, the terminal device generates a temporary public key and signs the temporary public key using system parameters, its own long-term private key and identity, generates a request message and sends it to the mobile edge server to complete its own authentication; the mobile edge server authenticates the collected request message of the terminal device and after the authentication is passed, selects a temporary key and signs the identity of the terminal device using the temporary key, system parameters and its own long-term private key and sends it to the cloud server to apply for a group identity from the cloud server; after the cloud server successfully verifies the signature, it returns the encrypted group identity to the mobile edge server; after the mobile edge server decrypts the group identity, it calculates the group session key and sends it to the terminal device to complete the response; after receiving the response message from the mobile edge server, the terminal device generates the group session key and completes the key confirmation.

2. The method for group device identity authentication and key agreement in a mobile edge computing environment based on distributed learning according to claim 1, characterized in that: The terminal device generates a temporary public key and signs the temporary public key using system parameters, its own long-term private key and identity identifier, and sends the signature to the mobile edge server, specifically including: Terminal Equipment (ED) i Randomly select an integer As a temporary private key, and calculate the temporary public key Then calculate the intermediate parameter k i,1 and k i,2 : in, Indicates terminal equipment ED i T i is a timestamp string, state2 is a message identification string corresponding to the group communication message, Indicates terminal equipment ED i The long-term public key; then calculate the intermediate parameters Finally generate the signature The signature and signature related information form a request message Sent to the mobile edge server MEC j ;in, Indicates terminal equipment ED i The long-term private key, Represents the Mobile Edge Server MEC j The long-term public key.

3. The method for group device identity authentication and key agreement in a mobile edge computing environment based on distributed learning according to claim 2, characterized in that: The mobile edge server authenticates the collected request messages from the terminal devices, specifically including: Mobile Edge Server (MEC) j Collect the request messages received from n terminal devices within the time interval δ and calculate To complete the identity authentication of the terminal device; and Represents the mobile edge server MEC j Temporary public key and long-term private key, For terminal equipment ED i The long-term public key, T j1 For timestamp strings, P and P pub These are all system parameters.

4. The method for group device identity authentication and key agreement in a mobile edge computing environment based on distributed learning according to claim 2, characterized in that: The selecting of a temporary key and signing the identity of the terminal device using the temporary key, system parameters and its own long-term private key and sending the signature to the cloud server specifically includes: Mobile Edge Server (MEC) j choose As a temporary private key, and calculate the temporary public key Then calculate the intermediate parameter k j,1 and k j,2 : Among them, T j1 For timestamp string; then calculate the intermediate parameters Indicates the terminal device MEC j The long-term private key finally generates the request message Send to the cloud server.

5. The method for group device identity authentication and key agreement in a mobile edge computing environment based on distributed learning according to claim 1, characterized in that: After the cloud server successfully verifies the signature, it returns the encrypted group identity to the mobile edge server, specifically including: After receiving the signature, the cloud server verifies the signature and generates a group identity for the group if the verification passes. <GID j ,VT j > Among them, GID j is the identification string, VT j is a timestamp string, and the group identity is identified by the session key between the mobile edge server and the cloud server. <GID j ,VT j > After encryption, it is sent to the mobile edge server MEC j .

6. The method for group device identity authentication and key agreement in a mobile edge computing environment based on distributed learning according to claim 4, characterized in that: After the mobile edge server decrypts and obtains the group identity, it calculates the group session key and sends it to the terminal device to complete the response, specifically including: Mobile Edge Server (MEC) j After receiving the message from the cloud server, the session key between the mobile edge server and the cloud server is used to decrypt the message to obtain the group identity. <GID j ,VT j >; Calculate the intermediate parameter k first e,1 and k e,2 : Among them, T j2 For timestamp string; then calculate the intermediate parameters Then calculate the group session key And generate the signature C of the group session key according to the following process j : The signature and signature related information form the response information Sent to terminal device ED i Completion response; PGID j and η are intermediate parameters, P is a system parameter, Indicates the identity of the mobile edge server.

7. The method for group device identity authentication and key agreement in a mobile edge computing environment based on distributed learning according to claim 6, characterized in that: After receiving the response message from the mobile edge server, the terminal device generates a group session key and completes key confirmation, specifically including: Terminal Equipment (ED) i After receiving the response message from the mobile edge server, calculate Then generate the group session key And verify the equation Is it true? If so, store the group session key gsk securely. i , and start communication within the group.

8. A group device identity authentication and key agreement system in a mobile edge computing environment based on distributed learning, characterized by: include: Trusted center, terminal devices, mobile edge servers and cloud servers; The trusted center is used to generate and publish system parameters during the initialization phase. Specifically, the trusted center selects the cyclic point group G on the elliptic curve, sets the group generator P∈G, the order to q, and the security parameter to λ; selects the one-way hash functions h1, h2, h3, h4, and h5; and randomly selects the system master private key. And calculate the corresponding public key P pub =sP; publish system parameters {P,q,h1,h2,h3,h4,h5,P pub }; In the registration phase, the terminal device and the mobile edge server use the system parameters to complete the registration at the trusted center to obtain their respective long-term private keys and identities during the communication process, specifically including: the terminal device or the mobile edge server randomly selects an integer locally The intermediate parameter X = xP is calculated and {RID, X} is sent to the trusted center. RID is the real identity of the terminal device or mobile edge server. The trusted center verifies whether the RID is in the user list and within the registration validity period. If it is not in the user list or the registration information has expired, it randomly selects an integer for the terminal device or mobile edge server. And perform the following operations on the terminal device or mobile edge server: If it is a terminal device, encrypt the RID of the terminal device with the system master private key to generate the pseudonym PID of the terminal device, and calculate the intermediate parameters R = rP and y = r + sh1 (PID, R), and reply {PID, R, y} to the terminal device through a secure channel; If it is a mobile edge server, directly calculate the intermediate parameter R = rP, and directly use the RID of the mobile edge server to calculate y = r + sh1 (RID, R), and reply {RID, R, y} to the mobile edge server through a secure channel; After receiving the response from the secure channel, the terminal device or mobile edge server verifies the equation yP=R+h1(ID,R)P pub Is it true? If so, store it safely.<x,y> As its own long-term private key; where ID is the pseudonymous PID of the terminal device or the RID of the mobile edge server; The terminal device is configured to select a temporary public key during the authentication and key negotiation phase, sign the temporary public key using system parameters, its own long-term private key, and its identity, generate a request message, and send it to the mobile edge server to complete its own authentication; and generate a group session key upon receiving a response message from the mobile edge server to complete key confirmation; During the authentication and key negotiation phase, the mobile edge server is used to authenticate the collected request messages from the terminal devices. After authentication, the mobile edge server selects a temporary key and signs the terminal device's identity using the temporary key, system parameters, and its own long-term private key. The signature is then sent to the cloud server to request a group identity from the cloud server. The mobile edge server is also used to decrypt the obtained group identity, calculate the group session key, and send it to the terminal device to complete the response. The cloud server, in the authentication and key agreement phase, is used to verify the signature successfully and return the encrypted group identity to the mobile edge server.

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