A method and system for protecting vehicle identity privacy based on a certificateless authentication mechanism

Abstract

The application discloses a method for protecting vehicle identity privacy based on a certificateless authentication mechanism, and the method comprises the following steps: a mapping relationship between a vehicle user identity certificate P and a real identity is established and is stored in a trusted authorization agency in a safe mode, then a regional manager verifies and confirms the legal identity of a vehicle user, and issues a short-time valid pseudonym identity generation parameter for the vehicle user, and finally, the vehicle generates a complete communication pseudonym when having a communication demand, and the communication pseudonym is associated with a message. When a malicious event occurs, a supervisory department extracts a pseudonym identity parameter of a vehicle involved in the message and completes network isolation of the malicious vehicle. The application further discloses a system for protecting vehicle identity privacy based on the certificateless authentication mechanism.

Description

Technical Field

[0001] This invention relates to the field of vehicle network security technology, and in particular to a method and device for protecting vehicle identity privacy based on a certificateless authentication mechanism. Background Technology

[0002] Building a modern intelligent transportation system is an effective measure to solve current road safety problems. Through networked communication and coordinated cooperation among various transportation components, real-time monitoring and adjustment of road traffic can reduce the probability of vehicle accidents and improve road efficiency. As a key component of building an intelligent transportation system, on the one hand, vehicle-to-everything (V2X) networks help connected vehicles obtain current driving environment and road condition information, adjust driving status in a timely manner, and rationally plan driving routes, improving the driving experience for road users. On the other hand, traffic management departments can use V2X to monitor and allocate road traffic flow, achieving intelligent traffic management. Due to the mobile nature of vehicles, V2X uses wireless communication channels for message transmission. Commonly used wireless communication protocols include DSRC, LTE, and 5G NR. Different protocols have their own advantages and disadvantages in technical implementation and slightly different applicable scenarios. However, the openness of the transmission environment makes wireless links susceptible to external interference and adversary attacks, posing significant risks to message transmission and seriously threatening the data ecosystem security of V2X.

[0003] Privacy breaches are a major concern in the field of connected vehicle data security and are gradually becoming a bottleneck for connected vehicle applications. In recent years, with the improvement of personal information protection laws and the significant increase in citizens' awareness of information protection, privacy breaches have come into the public eye, and the privacy and security of connected vehicle users have also attracted widespread attention. In the connected vehicle environment, vehicle users obtain a comfortable driving experience by communicating with other nodes. Communication messages typically contain fixed information such as node ID and sending time, vehicle status information such as speed, direction of travel, and driving lane, or driving assistance information such as news and audio-visual content, which are modified according to different vehicle needs. During communication, since nodes mostly use wireless channels for message transmission, the message receiver needs to enable a verification mechanism to verify the legality and integrity of the received information, that is, to determine that the message comes from a legitimate or expected sender and has not been tampered with during transmission. In the identity verification process, users need to provide the required information to complete identity authentication. Transmitting the user's real identity-related identifiers helps improve verification efficiency. The openness of the communication environment makes it possible for other users to successfully obtain user data. With the obtained communication data, malicious attackers can deduce user information such as the location, driving trajectory, and even residential address of the communication participants, resulting in privacy breaches. How to reduce the risk of leakage of user information in the Internet of Vehicles (IoV) and enhance user confidence are problems that need to be solved in the current development of IoV.

[0004] Applying pseudonym technology in the Internet of Vehicles (IoV) and designing privacy protection schemes that meet user security needs can not only effectively protect users' sensitive information and enable anonymous vehicle communication, thereby increasing the user base, but also has important practical significance for promoting the development of the IoV field and building a safe and efficient transportation system. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of user privacy leakage and data untrustworthiness in vehicle-to-everything (V2X) communication. By combining blockchain technology, a lightweight authentication protocol based on certificateless pseudonyms is designed, and a method and system for dual verification of user identity and message integrity are completed through a non-interactive zero-knowledge proof protocol.

[0006] The present invention provides a method for protecting vehicle identity privacy based on a certificateless authentication mechanism, comprising the following steps:

[0007] A trusted authorized agency generates and broadcasts system common parameters to each unit in the system, including area managers, roadside units, and regulatory agencies. The area managers and roadside units receive the system common parameters and complete initialization.

[0008] The trusted authorization authority issues identity certificate P to the vehicle user and establishes and stores the mapping relationship between the identity certificate P and the real identity of the vehicle user.

[0009] The vehicle user sends a pseudonym parameter request message to the area administrator of the current area. The pseudonym parameter request message contains the vehicle user's identity certificate P.

[0010] The regional administrator receives and verifies the pseudonym parameter application message. If the verification is successful, the administrator sends the pseudonym generation parameter to the vehicle user and establishes a mapping relationship between the vehicle user's identity certificate P and the longest validity period of the pseudonym generation parameter, and stores the mapping relationship on the blockchain. Otherwise, the administrator discards the pseudonym parameter application message and ends the verification process.

[0011] The vehicle user receives and verifies the pseudonym generation parameters. If the verification is successful, the pseudonym generation parameters are saved and used to generate a communication pseudonym. If the verification fails, the pseudonym generation parameters are discarded and the verification process ends.

[0012] When a vehicle user sends a message, the message to be sent is first signed, and the communication pseudonym and the signed message are sent together; when a vehicle user receives a message, the received message is first verified. If the verification is successful, the message is accepted; otherwise, the message is discarded or the vehicle user who sent the message is reported.

[0013] When a report is received from a vehicle user, the regulatory agency determines whether the reported message is malicious. If so, the vehicle user who sent the malicious message will be isolated from the network; otherwise, the report will be discarded.

[0014] Furthermore, the trusted authorization authority issues an identity certificate P to the vehicle user, and establishes and stores a mapping relationship between the identity certificate P and the vehicle user's real identity, including:

[0015] The vehicle user submits identity registration information (RIM) to the trusted authorized agency. v The trusted authorization authority, based on the identity registration information RIM v The identity verification P is calculated as follows:

[0016] First calculate the identity registration information (RIM). v Hash function value:

[0017] H(RIM v )=H2(ID||Number||Owner||Telephone||Address)

[0018] Then calculate the identity verification P. Then, the mapping relationship between the identity certificate P and the real identity of the vehicle user is saved.<M,P>

[0019] Furthermore, the method also includes: after receiving the identity certificate P, the vehicle user verifies that the identity certificate P was indeed issued by the trusted authorized agency if the following equation is true, and the equation is as follows:

[0020]

[0021] Furthermore, the vehicle user sends a pseudonym parameter request message M1 to the area administrator of the current area, wherein the pseudonym parameter request message M1 = (R, LR, P, h(m), t1), where:

[0022]

[0023] LR=k+H(RIM v )×h(m)

[0024] h(m) = H1(R||P||LR)

[0025] Furthermore, the area manager receives and verifies the pseudonym parameter request message. If the verification is successful, the manager sends pseudonym generation parameters to the vehicle user, including:

[0026] After receiving the pseudonym parameter request message, the regional administrator first verifies the timeliness of the message: Δt = t - t1;

[0027] If Δt is less than the maximum communication delay that the area manager can accept, then the integrity of the pseudonym parameter request message is verified; otherwise, the pseudonym parameter request message is discarded and the verification process ends. The maximum communication delay is one of the system public parameters broadcast by the trusted authorization authority to the system participants.

[0028] The area manager verifies the integrity of the pseudonym parameter application message by calculating a hash function. If the verification is successful, the manager continues to verify the vehicle user's identity certificate P; otherwise, the pseudonym parameter application message is discarded and the verification process ends.

[0029] The area administrator verifies the vehicle user's identity certificate P by calculating. If the verification is successful, a pseudonym generation parameter is generated for the vehicle user and sent to the vehicle user through a secure channel. If the verification fails, the pseudonym parameter request message is discarded and the verification process ends.

[0030] Furthermore, the vehicle user uses zero-knowledge proof technology in conjunction with the pseudonym generation parameters to sign the message to be sent.

[0031] Furthermore, the vehicle users include the sending vehicle that sends the message and the receiving vehicle that receives the message;

[0032] When a report is received from a vehicle user, the regulatory agency determines whether the reported message is malicious. If so, the vehicle user who sent the malicious message is isolated from the network; otherwise, the report is discarded.

[0033] After the receiving vehicle verifies that the received message is an error or a false message, it sends the message to the regulatory agency. The regulatory agency receives the message and performs a consistency or similarity judgment on the message. If the judgment confirms that the message is a malicious message, it extracts the identity identifier of the sending vehicle from the message and writes it into the blockchain along with the message verification result. At the same time, it sends a system broadcast to the regional manager.

[0034] After receiving the system broadcast from the regulatory agency, the regional manager confirms whether the pseudonym generation parameters contained in the malicious message were issued by him. If so, he proactively updates the public-private key pair used by the regional manager to issue the pseudonym generation parameters, adds the verification key for issuing the pseudonym generation parameters contained in the malicious message to the revocation list and updates the revocation list. The regulatory agency then writes the revocation list into the blockchain and notifies the roadside unit.

[0035] The roadside unit broadcasts the updated cancellation list within its communication range. After receiving the broadcast from the roadside unit, the sending vehicle and the receiving vehicle check whether the verification key of their pseudonym generation parameter is in the updated cancellation list. If so, they re-apply for the pseudonym generation parameter from the area manager of the current area; otherwise, they ignore the broadcast from the roadside unit.

[0036] A second aspect of the present invention provides a system for protecting vehicle identity privacy based on a certificateless authentication mechanism, the system comprising:

[0037] A trusted authorization authority is used to issue identity certificates P to vehicle users, establish and store the mapping relationship between the identity certificates P and the real identities of the vehicle users, and at the same time, generate and broadcast system public parameters to each unit in the system through the system network.

[0038] The vehicle user has an information processing module for communicating with various units in the system and processing communication information. The information processing module receives and stores an identity certificate P issued by a trusted authorized agency, and sends a pseudonym parameter request message to the area administrator, the pseudonym parameter request message including the identity certificate P. When the area administrator generates and returns pseudonym generation parameters, the information processing module receives these parameters and creates a communication pseudonym from them. When the vehicle user sends a message, the information processing module signs the message, attaches the communication pseudonym, and then sends the message out.

[0039] The regional manager is responsible for receiving and verifying the pseudonym parameter application message sent by the vehicle user, and sending the pseudonym generation parameter to the vehicle user when the verification is successful. At the same time, the manager establishes a mapping relationship between the vehicle user's identity certificate P and the pseudonym generation parameter, and stores the mapping relationship on the blockchain.

[0040] The roadside unit is connected to the vehicle user, trusted authorized agency, and area administrator via a network.

[0041] Regulatory bodies are responsible for handling malicious messages and isolating vehicle users who send such messages from the network.

[0042] Furthermore, when a malicious message is received, the information processing module sends a report to the regulatory agency.

[0043] Furthermore, the regulatory agency receives and judges the report message. If it confirms that the report message is a malicious message, it extracts the identity of the vehicle user who sent the malicious message from the malicious message and writes it into the blockchain along with the malicious message. At the same time, it sends a system broadcast to the regional manager.

[0044] The regional manager receives the system broadcast from the regulatory agency and confirms whether the pseudonym generation parameters contained in the vehicle user's identity identifier were issued by it. If so, the regional manager actively updates the public-private key pair used to issue the pseudonym generation parameters, adds the verification key pair for issuing the pseudonym generation parameters contained in the malicious message to the revocation list, and writes the revocation list into the blockchain through the regulatory agency and notifies the roadside unit.

[0045] The roadside unit receives the revocation list and broadcasts it within its communication range. The vehicle user receives the broadcast from the roadside unit and confirms whether the verification key of its pseudonym generation parameter belongs to any item in the revocation list. If so, it re-applies for the pseudonym generation parameter from the area manager of the current area; otherwise, it ignores the broadcast from the roadside unit.

[0046] Compared with the prior art, the beneficial effects of the present invention mainly include:

[0047] (1) Regarding the identity authentication problem in the Internet of Vehicles, traditional mechanisms generally use pseudonym certificates for authentication, which can lead to single point of failure and high overhead. This invention proposes a blockchain-based security authentication model, which mainly includes a security authentication protocol and a data credibility assessment model. This model avoids the problem of high communication and storage overhead in certificate authentication and also achieves a dual improvement in user privacy protection and data availability.

[0048] (2) Based on the research of existing vehicle network identity authentication models, this invention improves the design of blockchain-based security authentication. In order to reduce the excessive frequency of operations by trusted authorized institutions, regional managers and regulatory agencies are introduced, and the immutability of blockchain is used to securely store network communication messages.

[0049] (3) In particular, this invention combines the resource characteristics of vehicle user nodes and uses a pseudonym self-generation method to revoke the pseudonyms of illegal vehicles by updating the issued public key, thereby achieving the purpose of forward security to protect user privacy information. At the same time, in order to prevent collusion attacks, the revocation process is designed to be completed by regional managers and regulatory agencies through collaborative computation, and the revocation results are publicly stored in the blockchain to achieve network isolation of illegal vehicles. Attached Figure Description

[0050] Figure 1 This is a flowchart illustrating a method for protecting vehicle identity privacy based on a certificateless authentication mechanism according to the present invention. Detailed Implementation

[0051] The following includes definitions of terms used in this application. The definitions include various examples and / or forms of components that can be used in implementation within the scope of the terminology, but the examples are not intended to limit the technical solutions of this application, but are merely used to explain and illustrate the technical solutions of this application.

[0052] Among them, the trusted authorized agency is the traffic management department or transportation department, which is responsible for issuing identity certificates P to vehicle users based on the original identity information of the vehicle.

[0053] Among them, regulatory agencies are responsible for collecting network traffic information and analyzing and processing malicious messages.

[0054] The regional manager is responsible for allocating and updating the pseudonym generation parameters for vehicle users. The regional manager is a fundamental node constituting zero-computation, possessing a physical entity that can be distributed across different geographical locations. It has abundant storage and computing resources, communication modules with vehicle user terminals and various cloud computing nodes, and operates as an independent node in the network, capable of local decision-making. In this embodiment, the regional manager possesses strong computing, storage, and communication capabilities, enabling it to maintain the normal operation of the blockchain system. The regional manager can receive or forward requests from vehicle users within its communication range, allocate pseudonym generation parameters to vehicles by verifying the vehicle user's identity certificate P, and write the allocated pseudonym generation parameter information into the blockchain. The immutable record of the blockchain ensures that the data cannot be modified or deleted.

[0055] Among them, the Roadside Unit (RSU) is deployed on both sides of the road to receive and forward communication messages from the vehicle side.

[0056] Among these features, vehicle users can communicate with neighboring vehicles and other units within the system.

[0057] Example 1

[0058] like Figure 1 As shown, a method for protecting vehicle identity privacy based on a certificateless authentication mechanism according to the present invention includes the following steps:

[0059] S1: The trusted authorized agency generates and broadcasts system common parameters to each unit in the system. Each unit in the system includes the area manager, roadside unit (RSU), and regulatory agency. The area manager and roadside unit (RSU) receive the system common parameters and complete initialization.

[0060] In this embodiment, the system common parameters generated and broadcast to each unit in the system by the trusted authorization authority include: Among them, G1, G2 and G TIt is a multiplicative cyclic group of order q, where q is a large prime number. g1 is a generator of group G1, and g2 is a generator of group G2. First, the trusted authorization agency defines a bilinear mapping: Then, the trusted authority selects two secure one-way hash functions. Finally, trusted authorized agencies are randomly selected. As the system private key SK TA = (x1, x2), and calculate the system public key.

[0061] S2: A trusted authorized agency issues an identity certificate P to the vehicle user and establishes and stores the mapping relationship between the identity certificate P and the real identity of the vehicle user.

[0062] As an embodiment of the present invention, the vehicle user submits its identity registration information (RIM) to the trusted authorization authority. v RIM v = (ID, Number, Owner, Telephone, Address). The identity registration information can also be adjusted according to actual needs. This is only an example used to explain the content of this application.

[0063] The trusted authorization agency registers RIM based on this identity information. v The identity verification P is calculated as follows:

[0064] First calculate the identity registration information (RIM). v Hash function value:

[0065] H(RIM v )=H2(ID||Number||Owner||Telephone||Address)

[0066] Then calculate the identity verification P.

[0067] Then, the mapping relationship between the identity certificate P and the real identity information of the vehicle user is stored in the offline database.<M,P> And send the identity verification P to the corresponding vehicle user.

[0068] After receiving the identity certificate P issued by the trusted authorized agency, the vehicle user first verifies whether the following equation holds true. If it does, then the identity certificate P is confirmed to have been issued by the trusted authorized agency:

[0069]

[0070] Among them: RIM vVehicle user registration information includes the vehicle owner's ID card number, vehicle license plate number, owner's name, address, and contact information;

[0071] H(RIM v ), H'(RIM v The hash digest of the vehicle registration information is used for both;

[0072] P is the vehicle user's identification document;

[0073] x1 and x2 are the public keys of trusted authorized institutions, respectively;

[0074] g1 is a generator of the multiplicative cyclic group G1, and g2 is a generator of the multiplicative cyclic group G2.

[0075] e is a bilinear mapping.

[0076] The above formula is based on the q-sdh assumption.

[0077] S3: The vehicle user sends a pseudonym parameter request message to the area administrator of the current area. The pseudonym parameter request message contains the vehicle user's identity certificate P.

[0078] In this embodiment, the vehicle user calculates a pseudonym parameter application message M1 containing identity verification P and sends it to the area administrator of the current area where the vehicle is located. Wherein:

[0079] M1 = (R, LR, P, h(m), t1)

[0080]

[0081] LR=k+H(RIM v )×h(m)

[0082] h(m) = H1(R||P||LR)

[0083] In the above equations, RIM v Vehicle user registration information includes the vehicle owner's ID card, vehicle license plate number, and other relevant details.

[0084] The person's name, address, and contact information are required.

[0085] H(RIM v ) is a hash digest of the vehicle user registration information; h(m) is used to prevent data from being tampered with or forged during transmission.

[0086] P is the vehicle user's identification document;

[0087] k is a random number selected by the vehicle user;

[0088] t1 is the time when the pseudonym parameter request message M1 is sent;

[0089] LR is used to verify that the vehicle indeed possesses H (RIM). v )

[0090] To ensure zero-knowledge protection, the vehicle user terminal first generates a random number k. This random number is used to protect H(RIM). v If it cannot be extracted by the area manager, it will be mapped onto the elliptic curve group G2, denoted as S.

[0091] H(RIM) v Mapping H(RIM) onto elliptic curve G2 prevents H(RIM) from being mapped onto elliptic curve G2. v This information is directly obtained by the regional administrator and is denoted as R.

[0092] g2 is a generator of the multiplicative cyclic group G2.

[0093] S4: The regional administrator receives and verifies the pseudonym parameter application message. If the verification is successful, the administrator sends the pseudonym generation parameter to the vehicle user and establishes a mapping relationship between the vehicle user's identity certificate P and the longest validity period of the pseudonym generation parameter. The mapping relationship is then stored on the blockchain. Otherwise, the pseudonym parameter application message is discarded and the verification process ends.

[0094] In this embodiment, after receiving the pseudonym parameter request message from the vehicle user, the area administrator first verifies the timeliness of the message by calculating Δt = t - t1. Here, t is the timestamp when the message is received, t1 is the timestamp when the message is sent, and Δt represents the difference between the message sending time and the receiving time.

[0095] If Δt is less than the maximum communication delay that the area manager can accept, it means that the currently received pseudonym parameter request message is valid, and then the next step of verification is performed; if Δt is greater than the maximum communication delay that the area manager can accept, the pseudonym parameter request message is discarded.

[0096] Once the message timeliness verification is successful, the regional administrator verifies the integrity of the pseudonym parameter request message by calculating a hash function. If the verification is successful, the administrator continues to verify the vehicle user's identity certificate P; otherwise, the pseudonym parameter request message is discarded and the verification process ends.

[0097] In this embodiment, the area manager calculates a hash function h'(m). If h'(m) and h(m) are equal, the integrity of the message is confirmed; otherwise, the pseudonym parameter is discarded to request the message and the verification process ends. The verification formula is as follows:

[0098] S'=g2 LR R -h(m)h'(m)=H1(R||S'||P)

[0099] Where P is the vehicle user's identity certificate, g2 is the generator of the multiplicative cyclic group G2; h(m) is used to prevent data from being tampered with or forged during transmission, and h'(m) is used to verify whether the data has been tampered with or forged during transmission.

[0100] H(RIM) v Mapping H(RIM) onto elliptic curve G2 prevents H(RIM) from being mapped onto elliptic curve G2. v This information is directly obtained by the regional administrator and is denoted as R.

[0101] S′ corresponds to parameter S in the process of calculating the pseudonym parameter request message.

[0102] Once the message integrity verification is successful, the area administrator calculates and verifies the vehicle user's identity certificate P. If the verification is successful, a pseudonym generation parameter is generated for the vehicle user and sent to the vehicle user through a secure channel. If the verification fails, the pseudonym parameter request message is discarded, and the verification process ends.

[0103] In this embodiment, e(P, Rg2) is verified by calculation. x1 g2 x2 If the condition ) = e(g1, g2) is true, then the identity certificate P of the vehicle user is valid; if not, then the pseudonym parameter request message is discarded and the verification process ends.

[0104] Once the timeliness, integrity, and legality of the vehicle user's identity are verified, the regional administrator generates pseudonym generation parameters for the vehicle user and sends them to the vehicle user through a secure channel.

[0105] In this embodiment, the area administrator calculates the pseudonym generation parameters (a, b, T) and sends them to the applying vehicle user via a secure channel, while simultaneously mapping the relationship...<P,T> It is stored on the blockchain; where P is the vehicle user's identity certificate and T is the maximum validity period of the pseudonym generation parameter issued by the regional administrator.

[0106] In the pseudonym generation parameters, 'a' and 'b' are random numbers obtained by randomizing the key used to issue the pseudonym generation parameters by the area administrator. These random numbers are used to verify for vehicle users whether the received pseudonym generation parameters were issued by the requesting area administrator. The vehicle user's identity identifier RP is a mapping of the longest validity period T of the pseudonym generation parameters onto a multiplicative cyclic group. It is used to trace and revoke the owner of the communication pseudonym while protecting the pseudonym generation parameters and user privacy. The randomization calculation process is as follows:

[0107]

[0108] Among them, g1 y Generate parameters and issue a key for the pseudonym of the current area administrator;

[0109] c is a random parameter selected by the regional manager;

[0110] g1 is a generator of the multiplicative cyclic group G1, and g2 is a generator of the multiplicative cyclic group G2.

[0111] T represents the maximum validity period of the pseudonym generation parameters issued by the regional administrator;

[0112] e is a bilinear mapping.

[0113] S5: The vehicle user receives and verifies the pseudonym generation parameters. If the verification is successful, the pseudonym generation parameters are saved and used to generate a communication pseudonym. If the verification fails, the pseudonym generation parameters are discarded and the verification process ends.

[0114] In this embodiment, the vehicle user's message verification process is as follows:

[0115] After receiving the pseudonym generation parameters, the vehicle user first verifies the message's timeliness: Δt = t - t', where t is the timestamp of the message received by the vehicle user; t' is the maximum validity period of the pseudonym generation parameters; and Δt is the difference between the message reception time and the maximum validity period.

[0116] If the timestamp of the message received by the vehicle user is within the maximum validity period, the verification is successful, and the pseudonym generation parameter is received and saved. Otherwise, the message is discarded and the verification ends.

[0117] After the message timeliness verification passes, the vehicle user further verifies the legitimacy of the message's source: e(a, g2) = e(b, Y). Here, a and b are pseudonym generation parameters, g2 is the generator of the multiplicative cyclic group G2, Y is the pseudonym generation parameter verification key claimed by the current area administrator, and e is a bilinear mapping. The pseudonym generation parameter verification key claimed by the current area administrator and the pseudonym generation parameter signing key of the current area administrator are a key pair in an asymmetric cryptographic algorithm.

[0118] Once the message's timeliness and source legitimacy are verified, the vehicle user receives and saves the pseudonym generation parameters fed back by the area administrator of the current area, and uses the pseudonym generation parameters to generate a communication pseudonym.

[0119] In this embodiment, the vehicle user generates a communication pseudonym PID = (A, D, Q) by randomizing the pseudonym generation parameters according to different communication objects or based on a set time. The randomization calculation formula is as follows:

[0120] A = a f C = b f D = b h·f

[0121] h = H2(t2), Q = W T·(-l) ·C

[0122] Where A, D, and Q represent different random numbers in the communication pseudonyms;

[0123] It is a random number selected by the vehicle user;

[0124] t2 represents the generation time of the current communication pseudonym;

[0125] H2 is a secure hash function; W is the verification public key of the regulatory agency;

[0126] C is the result of randomizing the pseudonym parameter b using a random number selected from the vehicle side;

[0127] T represents the maximum validity period of the vehicle user pseudonym generation parameter, which is used here as a traceability identifier for the vehicle user pseudonym generation parameter.

[0128] S6: When a vehicle user sends a message, the message to be sent is first signed, and the communication pseudonym and the signed message are sent together. The message Msg... vi = (M, (A, D, Q), K, N, σ, t2, t3), and its calculation process is as follows:

[0129]

[0130]

[0131] H(M)=H1(M||t2||A||C||Q||K||N||E)

[0132] Where H1 is a secure hash function; f and l are random numbers selected by the vehicle user;

[0133] M represents vehicle driving information, including speed, distance, road conditions, etc.

[0134] t2 is the generation time of the current communication pseudonym, and t3 is the message sending time;

[0135] σ refers to the signature generated by the vehicle user for the current message;

[0136] (A, D, Q) are communication pseudonyms P

[0137] K is a parameter used to verify message integrity, and N is a parameter used to verify the legitimacy of message identity.

[0138] To achieve zero knowledge, E is the result of randomizing C using the random number 1; C is the result of randomizing the pseudonym parameter b using the random number selected by the vehicle.

[0139] g1 is the multiplication cyclic group; C is the result of randomizing the pseudonym parameter b using a random number selected from the vehicle end.

[0140] G1 is a generator of the multiplicative cyclic group G2, and g2 is a generator of the multiplicative cyclic group G2.

[0141] When a vehicle user receives a message, they first verify the message. If the verification is successful, the message is accepted; otherwise, the message is discarded or the vehicle user who sent the message is reported.

[0142] In this embodiment, the vehicle user receiving the message verifies the received message using the communication pseudonym of the vehicle user sending the message and a signature of the message. The communication pseudonym and signature are sent along with the message. The specific verification steps are as follows:

[0143] First, verify the message's timeliness: Δt = t - t3, where t is the timestamp when the message was received and t3 is the timestamp when the message was sent. If Δt exceeds the system's preset time limit, the message is considered unreceived and discarded, and the verification process ends.

[0144] If the message timeliness verification passes, the communication pseudonym is further verified to be within its validity period. If it is, the next verification step is performed; otherwise, the message is discarded.

[0145] The validity period verification of the communication pseudonym is as follows: Δt = t - t2, where t is the timestamp when the message is received, and t2 is the generation time of the current communication pseudonym. If Δt is greater than the system's preset validity period, the verification fails, and the message is discarded.

[0146] If the validity period of the communication pseudonym is verified, the legality of the communication pseudonym of the vehicle user sending the message is further verified, including: whether it is genuine, whether it meets network access requirements, and whether the current communication pseudonym has been revoked; the verification formula is as follows:

[0147]

[0148] In the formula, e is the bilinear mapping function; A and D are different random numbers in the communication pseudonym; E is the result of randomizing C; g2 is the generator of the multiplicative cyclic group G2; H2'(t2) represents the message digest calculated on the secure hash function H2 for the validity period of the current pseudonym generation parameter; Y is the pseudonym generation parameter verification key claimed by the area administrator who generated the pseudonym generation parameter; and N is the parameter used to verify the legitimacy of the message identity.

[0149] If the communication pseudonym of the vehicle user sending the message passes the validity verification, the message integrity is finally verified, i.e., whether the message has been tampered with. The verification formula is as follows:

[0150]

[0151] H'(M)=H1(M||t2||A||C'||Q||K||N||E)

[0152] If the timeliness of the message, the validity period of the communication pseudonym of the vehicle user sending the message, the legality of the identity, and the integrity of the message are all verified, it is determined that the message was sent by a legitimate vehicle, has not been tampered with during transmission, and may be helpful in adjusting the driving status, therefore it is received.

[0153] When a vehicle user enters a densely trafficked environment, if n messages need to be processed (where n is a natural number greater than 1), the following processing method can be used to improve message verification speed. The specific calculation is as follows:

[0154] First, verify identity legitimacy in batches using the following formula:

[0155]

[0156] Then, use the following formula to complete the batch verification of message integrity:

[0157]

[0158] t is the timestamp when the message was received;

[0159] t2 is the generation time of the current communication pseudonym;

[0160] σ represents the signature in the received message;

[0161] e is a bilinear mapping;

[0162] g1 is the generator of the multiplicative cyclic group G1, and g2 is the generator of the multiplicative cyclic group G2; the remaining parameters have the same meaning as the parameters in this embodiment.

[0163] S7: When an error or false message occurs, this invention uses a regulatory agency to handle malicious messages and isolate the vehicle user sending the malicious message from the network. The vehicle user includes the sending vehicle that sends the message and the receiving vehicle that receives the message. Once the receiving vehicle verifies that the received message is an error or false message, the regulatory agency and regional management can trace the vehicle's identity document P based on the message content, and, if necessary, obtain authorization from the TA to track the vehicle's true identity, and the TA can revoke the user's registration.

[0164] When the sending vehicle receives a message, if the verification of the legality of the communication pseudonym or the integrity of the message fails, the received message is deemed to be erroneous or false, and the sending vehicle is reported.

[0165] The reporting vehicle operates as follows: The receiving vehicle sends the erroneous or false message to the regulatory agency. The regulatory agency receives the message and then collects information on the environment, time, location, or other relevant information of the reporting vehicle from the Roadside Unit (RSU) and other participating units in the vehicle-to-everything (V2X) network. This information is used to determine the consistency or similarity of the message. If the message is confirmed to be malicious, then the following calculation is performed: RP' = e((QC) -1 ) -z N) Extract the identity identifier RP′ of the sending vehicle from the message, and store the identity identifier RP′ together with the judgment result of the malicious message in the blockchain, while sending a system broadcast to the regional administrator.

[0166] Upon receiving a system broadcast from the regulatory agency, the regional manager searches the blockchain for vehicle information matching the identity identifier RP'. If it is confirmed that the pseudonym generation parameters contained in the malicious message were sent by the manager, then the manager updates the public-private key pair used to issue the pseudonym generation parameters, adds the verification key of the pseudonym generation parameters of the vehicle that sent the malicious message to the revocation list, and simultaneously notifies the regulatory agency to write the updated revocation list into the blockchain and notify the roadside unit.

[0167] The roadside unit broadcasts the updated revocation list within its communication range. After receiving the broadcast from the roadside unit, the sending vehicle and the receiving vehicle check whether the public-private key pair for issuing their pseudonym generation parameters is in the updated revocation list. If so, they reapply for pseudonym generation parameters from the area administrator of the current area; otherwise, they ignore the broadcast from the roadside unit.

[0168] Example 2

[0169] The following provides a further description of the system for protecting vehicle identity privacy based on a certificateless authentication mechanism provided by the present invention. The system includes:

[0170] A trusted authorization authority is used to issue identity certificates P to vehicle users, establish and store the mapping relationship between the identity certificates P and the real identities of the vehicle users, and generate and broadcast system public parameters to each unit in the system through the system network.

[0171] The vehicle user has an information processing module for communicating with various units in the system and processing communication information. This module receives and stores an identity certificate P issued by a trusted authorized authority and sends a pseudonym parameter request message to the area administrator, the pseudonym request message including the identity certificate P. When the area administrator generates and returns pseudonym generation parameters, the information processing module receives these parameters and creates a communication pseudonym from them. When the vehicle user sends a message, the information processing module signs the message, attaches the communication pseudonym, and then sends the message.

[0172] The regional administrator is responsible for receiving and verifying the pseudonym parameter request message sent by the vehicle user. When the verification is successful, the administrator sends the pseudonym generation parameter to the vehicle user, establishes a mapping relationship between the vehicle user's identity certificate P and the pseudonym generation parameter, and stores the mapping relationship on the blockchain.

[0173] The roadside unit is connected to the vehicle user, trusted authorized agency, and area administrator via a network.

[0174] Regulatory bodies are responsible for handling malicious messages and isolating vehicle users who send such messages from the network.

[0175] Upon receiving a malicious message, the information processing module sends a report message to the regulatory agency. The regulatory agency receives and judges the report message. If the report message is confirmed to be malicious, it extracts the identity of the vehicle user who sent the malicious message from the malicious message and writes it into the blockchain along with the malicious message. At the same time, it sends a system broadcast to the regional administrator.

[0176] The area manager receives the system broadcast from the regulatory agency and confirms whether the pseudonym generation parameters contained in the vehicle user's identity identifier were issued by them. If so, the area manager proactively updates the public-private key pair used to issue the pseudonym generation parameters, adds the verification key pair used to issue the pseudonym generation parameters contained in the malicious message to the revocation list, and writes the revocation list into the blockchain through the regulatory agency and notifies the roadside unit.

[0177] The roadside unit receives the revocation list and broadcasts it within its communication range. The vehicle user receives the broadcast from the roadside unit and confirms whether the verification key of its pseudonym generation parameter belongs to any item in the revocation list. If so, it re-applies for the pseudonym generation parameter from the area manager of the current area; otherwise, it ignores the broadcast from the roadside unit.

[0178] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for protecting vehicle identity privacy based on a certificateless authentication mechanism, characterized in that, The method includes the following steps: A trusted authorized agency generates and broadcasts common system parameters to each unit in the system, including area managers, roadside units, and regulatory agencies. The area managers and roadside units receive the common system parameters and complete initialization. The trusted authorization authority issues identity certificate P to the vehicle user and establishes and stores the mapping relationship between the identity certificate P and the real identity of the vehicle user; The vehicle user sends a pseudonym parameter request message to the area administrator of the current area. The pseudonym parameter request message contains the vehicle user's identity certificate P. The regional administrator receives and verifies the pseudonym parameter application message. If the verification is successful, the administrator sends the pseudonym generation parameter to the vehicle user and establishes a mapping relationship between the vehicle user's identity certificate P and the longest validity period of the pseudonym generation parameter, and stores the mapping relationship on the blockchain. Otherwise, the administrator discards the pseudonym parameter application message and ends the verification process. The vehicle user receives and verifies the pseudonym generation parameters. If the verification is successful, the pseudonym generation parameters are saved and used to generate a communication pseudonym. If the verification fails, the pseudonym generation parameters are discarded and the verification process ends. When a vehicle user sends a message, the message to be sent is first signed, and the communication pseudonym and the signed message are sent together; when a vehicle user receives a message, the received message is first verified. If the verification is successful, the message is accepted; otherwise, the message is discarded or the vehicle user who sent the message is reported. When a report is received from a vehicle user, the regulatory agency determines whether the reported message is malicious. If so, the vehicle user who sent the malicious message will be isolated from the network; otherwise, the report message will be discarded. The trusted authorization authority issues identity certificate P to the vehicle user and establishes and stores a mapping relationship between the identity certificate P and the vehicle user's real identity, including: The vehicle user submits identity registration information RIMv to the trusted authorization agency, and the trusted authorization agency calculates identity verification P based on the identity registration information RIMv. The calculation process is as follows: First calculate the identity registration information (RIM). v Hash function value: Then calculate the identity verification P. Then, the mapping relationship between the identity certificate P and the real identity of the vehicle user is saved.<M,P> ； The method further includes: after receiving the identity certificate P, the vehicle user verifies that the identity certificate P was indeed issued by the trusted authorized agency if the following equation is true, and the equation is as follows: ； The vehicle users include the sending vehicle that sends the message and the receiving vehicle that receives the message; When a vehicle user reports a malicious message, the regulatory agency determines whether the message is malicious. If so, the vehicle user who sent the malicious message is isolated from the network; otherwise, the report is discarded. After the receiving vehicle verifies that the received message is an error or a false message, it sends the message to the regulatory agency. The regulatory agency receives the message and performs a consistency or similarity judgment on the message. If the judgment confirms that the message is a malicious message, it extracts the identity identifier of the sending vehicle from the message and writes it into the blockchain along with the message verification result. At the same time, it sends a system broadcast to the regional manager. After receiving the system broadcast from the regulatory agency, the regional manager confirms whether the pseudonym generation parameters contained in the malicious message were issued by him. If so, he proactively updates the public-private key pair used by the regional manager to issue the pseudonym generation parameters, adds the verification key used to issue the pseudonym generation parameters contained in the malicious message to the revocation list and updates the revocation list. The regulatory agency then writes the revocation list into the blockchain and notifies the roadside unit. The roadside unit broadcasts the updated cancellation list within its communication range. After receiving the broadcast from the roadside unit, the sending vehicle and the receiving vehicle check whether the verification key of their pseudonym generation parameter is in the updated cancellation list. If so, they re-apply for the pseudonym generation parameter from the area manager of the current area; otherwise, they ignore the broadcast from the roadside unit.

2. The method according to claim 1, characterized in that, The vehicle user sends a pseudonym parameter request message M1 to the area administrator of the current area. in: 。 3. The method according to claim 1, characterized in that, The area manager receives and verifies the pseudonym parameter request message. If the verification is successful, the manager sends pseudonym generation parameters to the vehicle user, including: After receiving the pseudonym parameter request message, the regional administrator first verifies the timeliness of the message: ; If Δt is less than the maximum communication delay that the area manager can accept, then the integrity of the pseudonym parameter request message is verified. Otherwise, the pseudonym parameter request message is discarded and the verification process ends. The maximum communication delay is one of the system public parameters broadcast by the trusted authorization authority to each unit in the system. The area manager verifies the integrity of the pseudonym parameter application message by calculating a hash function. If the verification is successful, the manager continues to verify the vehicle user's identity certificate P; otherwise, the pseudonym parameter application message is discarded and the verification process ends. The area manager verifies the vehicle user's identity certificate P by calculation. If the verification is successful... The system generates pseudonym generation parameters for the vehicle user and sends them to the vehicle user via a secure channel. If the verification fails, the pseudonym parameter request message is discarded, and the verification process ends.

4. The method according to claim 1, characterized in that, The vehicle user uses zero-knowledge proof technology in conjunction with the pseudonym generation parameters to sign the message to be sent.

5. A system for protecting vehicle identity privacy based on a certificateless authentication mechanism, the system being used to perform the method as described in claim 1, characterized in that: The system includes: a trusted authorization authority, which issues identity certificates P to vehicle users, establishes and stores the mapping relationship between the identity certificates P and the real identities of the vehicle users, and generates and broadcasts system public parameters to each unit in the system through the system network. The vehicle user has an information processing module for communicating with various units in the system and processing communication information. The information processing module receives and stores an identity certificate P issued by a trusted authorized agency, and sends a pseudonym parameter request message to the area administrator, the pseudonym parameter request message including the identity certificate P. When the area administrator generates and returns pseudonym generation parameters, the information processing module receives these parameters and creates a communication pseudonym from them. When the vehicle user sends a message, the information processing module signs the message, attaches the communication pseudonym, and then sends the message out. The area manager is responsible for receiving and verifying pseudonym parameter request messages sent by the vehicle user. Upon successful verification, a pseudonym generation parameter is sent to the vehicle user, and a mapping relationship is established between the vehicle user's identity certificate P and the pseudonym generation parameter, which is then stored on the blockchain. The roadside unit is connected to the vehicle user, trusted authorized agency, and area manager via a network. Regulatory bodies are responsible for handling malicious messages and isolating vehicle users who send such messages from the network.

6. The system according to claim 5, characterized in that: When a malicious message is received, the information processing module sends a report to the regulatory agency.

7. The system according to claim 6, characterized in that: The regulatory agency receives and judges the report message. If it confirms that the report message is a malicious message, it extracts the identity of the vehicle user who sent the malicious message from the malicious message and writes it into the blockchain along with the malicious message. At the same time, it sends a system broadcast to the regional manager. The regional manager receives a system broadcast from the regulatory agency and confirms whether the pseudonym generation parameters contained in the vehicle user's identity identifier were issued by them. If so, the regional manager proactively updates the public-private key pair used to issue the pseudonym generation parameters, adds the verification key used to issue the pseudonym generation parameters contained in the malicious message to the revocation list, updates the revocation list, and writes the revocation list into the blockchain through the regulatory agency and notifies the roadside unit. The roadside unit receives the revocation list and broadcasts it within its communication range. The vehicle user receives the broadcast from the roadside unit and confirms whether the verification key of their pseudonym generation parameters belongs to any item in the revocation list. If so, the vehicle user reapplies for pseudonym generation parameters from the regional manager of the current area; otherwise, the vehicle user ignores the broadcast from the roadside unit.

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