Certificate-free identity authentication method and related devices based on blockchain

Abstract

This application discloses a certificateless identity authentication method and related apparatus based on blockchain, relating to the field of vehicle networking technology. The system includes: an on-board unit (OBTU), roadside units (Roadside Units), and a key generation center. All Roadside Units and all Key Generation Centers act as blockchain nodes, forming a blockchain. The OBTU communicates with the Key Generation Center to generate a vehicle pseudonym, a vehicle public key, and a vehicle private key. Subsequently, the OBTU uses the vehicle pseudonym, vehicle public key, and vehicle private key to send and receive messages and communicate with other vehicles. During this process, the vehicle's real identity and vehicle pseudonym are stored in the blockchain and queried within the blockchain. By introducing blockchain, this application stores the vehicle's real identity and vehicle pseudonym in the blockchain. Leveraging the distributed, traceable, and tamper-proof characteristics of blockchain, the security of certificateless identity authentication can be improved.

Description

Technical Field

[0001] This application relates to the field of vehicle networking technology, and in particular to a certificateless identity authentication method and related device based on blockchain. Background Technology

[0002] Vehicle-to-everything (V2X) communication is an application of the Internet of Things (IoT) in the transportation sector, aiming to improve traffic efficiency. Based on onboard units (OBUs) installed in vehicles, it effectively facilitates the dissemination of real-time traffic information, becoming a key technology for alleviating traffic problems. In real-world traffic scenarios, vehicles can obtain real-time safety-related traffic information through V2X, such as the speed and direction of surrounding vehicles and hazardous road conditions, thereby improving the driving experience and road safety. Typical V2X communication primarily employs three communication methods: wired / wireless connections, vehicle-to-vehicle (V2V) communication, and vehicle-to-roadside unit (RSU) communication. Wired / wireless connections connect vehicles or RSUs to the internet, while V2V and RSU communication are controlled via the Dedicated Short Range Communications (DSRC) protocol using the IEEE 802.11p standard for convenient short-range communication.

[0003] Vehicle-to-everything (V2X) and the Internet of Things (IoT) share some characteristics, but also have their own unique features. Both rely on device interconnection and data exchange to achieve intelligent management and operation. However, V2X has its own unique characteristics, including the high-speed mobility of vehicles, dynamic changes in network topology, high real-time requirements, and stricter security and privacy protection needs. These unique features present unique challenges to V2X in terms of data transmission reliability, low-latency communication, and security. Therefore, while V2X offers many advantages, greater attention should be paid to the security challenges in the information sharing process between vehicles. Due to the open nature of wireless communication channels in V2X, these channels can be compromised and controlled by malicious attackers, potentially leading to eavesdropping and modification of the data transmitted.

[0004] In the Internet of Vehicles (IoV), vehicles broadcast messages containing their identity information to communicate with other vehicles or infrastructure. Attackers can decrypt this identity information by stealing the sender's private information, threatening the safety of vehicle users' lives and property. While authentication is an effective means of addressing communication security issues, in traditional centralized systems, vehicle private information is centrally stored. Therefore, once a centralized system is compromised, all of the sender's private information will be leaked, leading to serious data and user privacy risks, and communication security will no longer be guaranteed. Furthermore, with the rapid development of IoV, a large number of vehicle nodes are connecting to this vast network, posing significant challenges to the big data storage, intelligent management, and information security of the entire IoV system. Traditional centralized data processing methods and centralized network architectures can no longer meet the high security, high reliability, and real-time response requirements of IoV data sharing. Therefore, researching new IoV security architectures and efficient and secure authentication schemes is of significant research value and importance for ensuring communication security and providing drivers with a comfortable driving environment.

[0005] In open connected vehicle environments, authentication plays a crucial role in improving communication security and mitigating security threats. Existing authentication schemes mainly include: Public Key Infrastructure (PKI) based authentication schemes, identity-based authentication schemes, and certificate-less signature-based authentication schemes. However, PKI-based authentication schemes suffer from the problem of vehicles struggling to manage and store a large number of public-private key pairs and related certificates. Identity-based authentication schemes rely on a Key Generation Center (KGC) generating a key for the vehicle entity using its own master key. This approach cannot guarantee non-repudiation because the KGC can abuse the vehicle's access capabilities to sign and decrypt any message, leading to key escrow issues. Compared to public key infrastructure (PKI)-based and identity-based authentication schemes, certificate-free signature-based authentication schemes offer several advantages. Unlike PKI-based schemes, certificate-free signature-based schemes do not require any certificates to ensure the validity of the public key. Therefore, the absence of certificates reduces communication, computation, and storage overhead. Unlike identity-based schemes, the KGC in certificate-free signature-based schemes is a semi-trusted authority that calculates a portion of the private key based on the user's identity and provides it to the user. The actual private key is calculated using a secret value and a portion of the private key. The KGC has no authority to access the user's private key, thus eliminating key escrow issues.

[0006] However, in certificate-free signature-based authentication schemes, the traditional centralized system is still used. In this case, the vehicle's private information is stored centrally. Therefore, once the centralized system is compromised, the sender's vehicle's private information will be completely leaked, which will bring serious data and user privacy security risks. Communication security will no longer be guaranteed. How to design a more secure certificate-free identity authentication scheme is still an urgent problem to be solved. Summary of the Invention

[0007] The purpose of this application is to provide a blockchain-based certificateless identity authentication method and related apparatus, which can improve the security of certificateless identity authentication.

[0008] To achieve the above objectives, this application provides the following solution:

[0009] In a first aspect, this application provides a blockchain-based certificateless identity authentication system, which includes: an on-board unit, a roadside unit, and a key generation center. The on-board unit is communicatively connected to the roadside unit, and the roadside unit is communicatively connected to the key generation center. All roadside units and all key generation centers serve as blockchain nodes, forming a blockchain.

[0010] The vehicle-mounted unit, installed on the vehicle, is used to send the vehicle's true identity to the key generation center;

[0011] The key generation center is used to generate a vehicle pseudonym based on the vehicle's real identity, return the vehicle pseudonym to the vehicle unit, and store the vehicle's real identity and vehicle pseudonym in the blockchain;

[0012] The vehicle-mounted unit is used to generate the first parameter based on a random number and send the vehicle pseudonym, message, and the first parameter to the key generation center.

[0013] The key generation center is used to generate a partial key based on the vehicle pseudonym, the message, and the first parameter, and then returns the partial key to the vehicle unit.

[0014] The on-board unit is used to generate the vehicle public key and vehicle private key based on partial keys;

[0015] When a vehicle sends a message, the on-board unit generates a message signature based on the vehicle pseudonym, vehicle public key, and vehicle private key, and sends the vehicle pseudonym, vehicle public key, message, signature, and timestamp to other vehicles.

[0016] When a vehicle receives a message, the on-board unit uses the vehicle pseudonym, vehicle public key, message, signature and timestamp to make a preliminary judgment on whether the message is valid. If the message is preliminarily judged to be valid, a pseudonym query request is sent to the roadside unit.

[0017] The roadside unit is used to query the blockchain based on the pseudonym query request, determine whether the vehicle pseudonym is valid based on the query result, and return the determination result of whether the vehicle pseudonym is valid to the vehicle unit.

[0018] The on-board unit is used to re-determine whether the message is valid based on the judgment result. If the message is valid again, the message is received.

[0019] Secondly, this application provides a blockchain-based certificateless identity authentication method, applied to the aforementioned blockchain-based certificateless identity authentication system, wherein the blockchain-based certificateless identity authentication method includes:

[0020] The vehicle unit sends the vehicle's real identity to the key generation center and receives the vehicle's pseudonym returned by the key generation center;

[0021] The vehicle unit generates the first parameter based on a random number and sends the vehicle pseudonym, message and the first parameter to the key generation center, and receives a partial key returned by the key generation center.

[0022] The on-board unit generates a vehicle public key and a vehicle private key based on a partial key;

[0023] When a vehicle sends a message, the on-board unit generates a message signature based on the vehicle pseudonym, vehicle public key, and vehicle private key, and sends the vehicle pseudonym, vehicle public key, message, signature, and timestamp to other vehicles.

[0024] When a vehicle receives a message, the on-board unit makes a preliminary judgment on the validity of the message based on the vehicle pseudonym, vehicle public key, message, signature, and timestamp. If the message is initially determined to be valid, it sends a pseudonym query request to the roadside unit and receives the judgment result on the validity of the vehicle pseudonym returned by the roadside unit. Based on the judgment result, it makes another judgment on the validity of the message. If the message is determined to be valid again, it receives the message.

[0025] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described blockchain-based certificateless identity authentication method.

[0026] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the aforementioned blockchain-based certificateless authentication method.

[0027] According to the specific embodiments provided in this application, this application has the following technical effects:

[0028] This application provides a certificateless identity authentication method and related apparatus based on blockchain, including: an on-board unit, a roadside unit, and a key generation center. All roadside units and all key generation centers act as blockchain nodes, forming a blockchain. The on-board unit sends the vehicle's real identity to the key generation center. The key generation center generates a vehicle pseudonym based on the vehicle's real identity, returns the vehicle pseudonym to the on-board unit, and stores the vehicle's real identity and vehicle pseudonym in the blockchain. The on-board unit generates a first parameter based on a random number and sends the vehicle pseudonym, a message, and the first parameter to the key generation center. The key generation center generates a partial key based on the vehicle pseudonym, the message, and the first parameter, and returns the partial key to the on-board unit. The on-board unit generates a vehicle public key and a vehicle private key based on the partial key. When a vehicle sends a message, the on-board unit (OBU) generates a message signature based on the vehicle's pseudonym, public key, and private key, and sends the pseudonym, public key, message, signature, and timestamp to other vehicles. When a vehicle receives a message, the OBU initially determines the message's validity based on the pseudonym, public key, message, signature, and timestamp. If the message is initially deemed valid, it sends a pseudonym query request to the roadside unit. The roadside unit queries the blockchain based on the query request, determines the validity of the vehicle's pseudonym based on the query result, and returns the validity result to the OBU. The OBU then re-determines the message's validity based on this result. If the message is again deemed valid, it accepts the message. This application introduces blockchain technology, storing the vehicle's true identity and pseudonym in the blockchain. Leveraging the distributed, traceable, and immutable characteristics of blockchain, the security of certificate-less authentication can be improved. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a connection diagram of a blockchain-based certificateless identity authentication system provided in Embodiment 1 of this application.

[0031] Figure 2 This is a comparative diagram showing the communication latency of different schemes provided in Embodiment 1 of this application.

[0032] Figure 3 This is a schematic diagram of the process flow for a blockchain-based certificateless identity authentication method provided in Embodiment 2 of this application.

[0033] Figure 4This is a schematic diagram of the structure of a computer device provided in Embodiment 3 of this application. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] Example 1

[0036] Currently, certificateless signature-based authentication schemes still rely on traditional centralized systems, which are insecure and inefficient due to the use of bilinear mapping operations. While existing certificateless signature-based authentication schemes have addressed security and privacy issues in the Internet of Vehicles (IoV) to some extent, they still face challenges related to the massive data storage, real-time processing, and user privacy security inherent in traditional centralized systems. Designing a more secure and efficient certificateless identity authentication scheme remains a hot topic. Blockchain, with its decentralized, transparent, and effective distributed storage and security management technology, can be applied to IoVs. Leveraging its distributed, secure, traceable, and tamper-proof characteristics, blockchain technology enables vehicles to use a decentralized system for information transmission, increasing trust between different entities and providing a reliable environment for information sharing, offering greater security than traditional centralized systems. Blockchain technology protects data from tampering, allowing multiple entities to jointly maintain the same account information. Information sharing reduces the burden on centralized entities, providing an effective way to address the security vulnerabilities of traditional centralized systems. Therefore, in the insecure and unstable communication links of the Internet of Vehicles, researching efficient and secure blockchain-based certificateless identity authentication schemes has high theoretical significance and practical application value.

[0037] Based on this, this embodiment provides a certificateless identity authentication system for the Internet of Vehicles (IoV) supported by blockchain. In the IoV environment, leveraging the distributed, traceable, and immutable characteristics of blockchain, and combining it with a certificateless cryptographic mechanism, a certificateless identity authentication scheme without bilinear pairings is proposed, such as... Figure 1 As shown, this embodiment provides a blockchain-based certificateless identity authentication system. The blockchain-based certificateless identity authentication system includes: an on-board unit, a roadside unit, and a key generation center. The on-board unit is communicatively connected to the roadside unit, and the roadside unit is communicatively connected to the key generation center. All roadside units and all key generation centers serve as blockchain nodes, forming a blockchain.

[0038] The vehicle-mounted unit, installed on the vehicle, is used to send the vehicle's true identity to the key generation center.

[0039] The key generation center is used to generate a vehicle pseudonym based on the vehicle's real identity, return the vehicle pseudonym to the on-board unit, and store the vehicle's real identity and vehicle pseudonym in the blockchain.

[0040] The vehicle-mounted unit is used to generate the first parameter based on a random number and send the vehicle pseudonym, message, and the first parameter to the key generation center.

[0041] The key generation center is used to generate a partial key based on the vehicle pseudonym, the message, and the first parameter, and then returns the partial key to the vehicle unit.

[0042] The on-board unit is used to generate the vehicle public key and vehicle private key based on partial keys.

[0043] When a vehicle sends a message, the on-board unit generates a message signature based on the vehicle pseudonym, vehicle public key, and vehicle private key, and sends the vehicle pseudonym, vehicle public key, message, signature, and timestamp to other vehicles.

[0044] When a vehicle receives a message, the on-board unit uses the vehicle pseudonym, vehicle public key, message, signature, and timestamp to make a preliminary judgment on whether the message is valid. If the message is preliminarily determined to be valid, a pseudonym query request is sent to the roadside unit.

[0045] The roadside unit is used to query the blockchain based on the pseudonym query request, determine whether the vehicle pseudonym is valid based on the query result, and return the determination result of whether the vehicle pseudonym is valid to the vehicle unit.

[0046] The on-board unit is used to re-determine whether the message is valid based on the judgment result. If the message is valid again, the message is received.

[0047] To ensure that the vehicle identity sent by the vehicle unit is indeed the vehicle's real identity and not a forged identity, the blockchain-based certificateless identity authentication system in this embodiment also includes a motor vehicle management unit, which is communicatively connected to the vehicle unit.

[0048] The on-board unit is used to send a request to the vehicle management unit to obtain the true identity.

[0049] The vehicle management unit is used to verify the vehicle's identity and return the vehicle's true identity to the on-board unit.

[0050] The key generation center is used to verify the vehicle's true identity with the motor vehicle management unit after receiving the vehicle's true identity, and to generate a pseudonym for the vehicle based on the true identity after verification.

[0051] In this embodiment, the blockchain includes a pseudonym blockchain and a revocation blockchain. The pseudonym blockchain stores valid vehicle pseudonyms and vehicle real identities, while the revocation blockchain stores invalid vehicle pseudonyms.

[0052] This embodiment, based on the vehicle-to-everything (V2X) communication architecture, introduces a key generation center as an institution to assist vehicles in generating vehicle public and private keys, a vehicle management unit (MVD) as an institution to verify vehicle identity, and a blockchain, with blockchain nodes including the key generation center and roadside units, such as... Figure 1 As shown, the blockchain-based certificateless identity authentication system of this embodiment includes: a key generation center, a roadside unit, an in-vehicle unit, a motor vehicle management unit, and a blockchain. The key generation center and the roadside unit communicate via a secure channel through wired communication. The roadside unit and the in-vehicle unit communicate via a dedicated short-range communication protocol (V2R). The in-vehicle units communicate with each other via a dedicated short-range communication protocol (V2V). The in-vehicle unit and the motor vehicle management unit communicate via wired communication.

[0053] The functions of each part are as follows:

[0054] (1) Key Generation Center: The key generation center plays the role of the management center in the vehicle-to-everything (V2X) system. In the V2X authentication scheme, the key generation center is mainly responsible for the registration and authentication of roadside units and vehicle-mounted units, generating the system master key, and publishing system parameters. The key generation center is the only entity in the V2X system that can reveal the true identity of a vehicle and can retrieve and decrypt the vehicle's true identity information from the blockchain.

[0055] (2) Roadside unit: The roadside unit can monitor the driving information of vehicles in the area it is responsible for, and can also feed back traffic information such as road conditions and weather information in the area to the vehicles in real time. The roadside unit has stronger computing power.

[0056] (3) On-board unit: An on-board unit is a physical unit installed in a vehicle and possessing certain computing capabilities, capable of actively or passively providing communication services to the vehicle. Each registered on-board unit is equipped with a tamper-proof device (TPD) for storing key values ​​or other data. The on-board unit can connect to surrounding wireless networks through its own wireless communication components to transmit information, thus enabling the vehicle to exchange messages with other vehicles or roadside units in the vicinity.

[0057] (4) Motor vehicle management unit: can be the motor vehicle management department to assign a unique real identity ID to the vehicle before it enters the vehicle network system.

[0058] (5) Blockchain: A decentralized underlying architecture was constructed using blockchain. A key generation center and roadside units were selected as blockchain nodes, and some blockchain nodes were selected as consensus nodes. For example, the key generation center was selected as a consensus node. The consensus nodes executed the PBFT (Practical Byzantine Fault Tolerance) consensus algorithm to complete the blockchain initialization. Two blockchains were used in the vehicle-to-everything (V2X) system to store different data. One blockchain stored the encrypted vehicle user's real identity, the generated vehicle pseudonym, and the corresponding vehicle public key; this can be called the pseudonym blockchain. The other blockchain stored the vehicle pseudonym that had been revoked after verification; this can be called the revocation blockchain.

[0059] In this embodiment, the blockchain can be a consortium blockchain.

[0060] The following describes the working process of the blockchain-based certificateless identity authentication system in this embodiment:

[0061] (a) The key generation center generates system parameters and initializes the blockchain.

[0062] (1) The key generation center generates an additive cyclic group G of order q, where q is a large prime number, q > 2k, and k is the input security parameter. The generator of the additive cyclic group G is denoted as P.

[0063] (2) The key generation center is selected from an elliptic curve y on a finite field. 2 =x 3 +ax+b(mod q), where the coefficient a, 4a 3 +27b 2 (modq)≠0, where mod is the modulo function and q is the order of the additive cyclic group.

[0064] (3) The key generation center selects five collision-resistant hash functions: Wherein, H0 is the first hash function, H1 is the second hash function, H2 is the third hash function, H3 is the fourth hash function, and H4 is the fifth hash function.

[0065] (4) The key generation center selects a first random number. Used as the system master key, and the system public key P is calculated. pub =sP, where P pub is the system public key, s is the first random number, and P is the generator of the additive cyclic group G.

[0066] (5) The key generation center publicly announces the system parameters Params = {G, q, P, P}. pub , H0, H1, H2, H3, H4}, and secretly store the first random number s.

[0067] (6) Blockchain initialization: During blockchain initialization, a certain number of consensus nodes are randomly selected to execute the PBFT consensus algorithm in order to participate in network consensus.

[0068] (ii) Vehicle initialization and registration.

[0069] (1) Assuming the vehicle initialization and registration process is performed in a secure channel, the vehicle's on-board unit sends a request to the vehicle management unit to obtain the vehicle's true identity. The vehicle management unit verifies the vehicle's identity and assigns the vehicle's true identity RID. i Return to the vehicle unit.

[0070] (2) The on-board unit will store the vehicle's real identity RID. i The key is sent to the key generation center, which can verify the existence of a genuine vehicle identity by communicating with the vehicle management unit. If the vehicle's identity exists (i.e., verification is correct), a second random number is selected. Calculate vehicle pseudonym PID i =y i +sH0(RID i ||T i Then, the key generation center will assign the vehicle pseudonym RID. i The information is returned to the onboard unit. Simultaneously, the key generation center sends the vehicle's alias (PID) to the system. i With the vehicle's real identity RID i Stored on a pseudonymous blockchain. Among them, PID i This is a pseudonym for the vehicle, which is a unique identifier generated for the vehicle by the key generation center. i s is the second random number, s is the first random number, H0 is the first hash function, and RID is the second random number. i For the vehicle's true identity, T i For timestamps.

[0071] It should be noted that if the vehicle initialization and registration process is performed in an insecure channel, the vehicle's true identity needs to be transmitted in encrypted form, and any existing encryption method can be used.

[0072] (3) The vehicle unit randomly selects a third random number. As a secret value, the first parameter X is calculated. i =x i P, and (PID) i ,mi ,X i () is sent to the key generation center. Where X... i x is the first parameter. i Let m be the third random number, P be the generator of the additive cyclic group, and m be the third random number. i For message.

[0073] (4) The key generation center receives the (PID) sent by the vehicle unit. i ,m i ,X i After that, randomly select a fourth random number. First calculate partial public key R i =r i P and the first hash value h i1 =H1(P pub ,PID i ,X i ,R i Then calculate part of the private key d. i =(r i +sh i1 ) mod q, and calculate the partial key (d) i ,R i This is sent to the corresponding onboard unit. Among them, R... i For a partial public key, r i Let h be the fourth random number, P be the generator of the additive cyclic group, and h be the fourth random number. i1 H1 is the first hash value, H1 is the second hash function, and P is the second hash function. pub For system public key, PID i X is a pseudonym for the vehicle. i d is the first parameter. i is a partial private key, s is the first random number, mod is the modulo function, and q is the order of the additive cyclic group.

[0074] (5) The on-board unit receives part of the key (d) i ,R i After that, verify d. i P = R i +h i1 P pub If the condition is met, a portion of the key is received and execution continues; otherwise, execution terminates. Where d... i Let P be a partial private key, P be the generator of the additive cyclic group, and R be a partial private key. i For a portion of the public key, h i1 P is the first hash value. pub This is the system's public key.

[0075] (6) The on-board unit sets its own vehicle public key PK. i =(X i ,Ri ) and vehicle private key SK i =(x i ,d i ), among which, PK i For the vehicle's public key, X i R is the first parameter. i For partial public keys, SK i For the vehicle's private key, x i The third random number, d i This is a partial private key.

[0076] (iii) Vehicle certification.

[0077] During vehicle authentication, to ensure the authenticity and integrity of messages, the vehicle must sign the sent messages and design the received messages. Specifically, the vehicle's onboard unit uses the vehicle's pseudonym PID. i Using vehicle public key PK i and vehicle private key SK i For message m i Sign and unsign.

[0078] (1) Signature

[0079] When a vehicle sends a message, the onboard unit generates a message signature based on the vehicle's pseudonym, public key, and private key, and then sends the pseudonym, public key, message, signature, and timestamp to other vehicles. At this point, the onboard unit randomly selects a fifth random number. Then for message m i The signature is calculated using the following formula:

[0080] U i =u i P;

[0081] Among them, U i The second parameter; u i is the fifth random number; P is the generator of the additive cyclic group.

[0082] σ i =h i4 ux+h i3 d i +h i2 x i ;

[0083] Where, σ i h is the third parameter. i4 The fourth hash value; u i The fifth random number; h i3 The third hash value; d i For partial private key; h i2 The second hash value; xi It is the third random number.

[0084] h i4 =H4(PID) i PK i ,m i U i );

[0085] Among them, h i4 H4 is the fourth hash value; H4 is the fifth hash function; PID i For vehicle pseudonyms; PK i For vehicle public key; m i For message; U i This is the second parameter.

[0086] h i3 =H3(PID) i ,R i ,m i U i );

[0087] Among them, h i3 H3 is the third hash value; H3 is the fourth hash function; PID i For vehicle names; R i For partial public keys; m i For message; U i This is the second parameter.

[0088] h i2 =H2(PID) i ,X i ,m i U i );

[0089] Among them, h i2 H2 is the second hash value; H2 is the third hash function; PID i For vehicle registration; X i m is the first parameter; i For message; U i This is the second parameter.

[0090] The vehicle-mounted unit will δ i =(U i ,σ i ) as a response to message m i The signature, and sent (PID) i PK i ,m i ,δ i ,T i This is given to other vehicles that need to communicate. Among them, PID i For vehicle pseudonyms, PK i For the vehicle's public key, mi For message, δ i For signature, T i For timestamps.

[0091] (2) Verification of signatures - Single vehicle message authentication

[0092] When a vehicle receives a message, the onboard unit (OIN) initially determines the message's validity based on the vehicle's pseudonym, public key, message name, signature, and timestamp. If the message is initially deemed valid, it sends a pseudonym query request to the roadside unit (Roadside Unit). The Roadside Unit then queries the blockchain based on the query request, determines the validity of the vehicle pseudonym based on the query result, and returns the result to the OIN. The OIN further determines the message's validity based on this result. If the message is deemed valid again, it accepts the message.

[0093] At this time, the vehicle unit receives the (PID) i PK i ,m i ,δ i ,T i To verify message m i The validity of the information and the legitimacy of the vehicle's identity. First, through the timestamp T... i Determine message m i Whether it is valid depends on whether the difference between the received message time and the timestamp is less than a preset difference. If so, then message m... i Valid; otherwise, message m i Invalid; if message m i If invalid, discard the message m directly. i Otherwise, if message m i If valid, the verification equation is checked based on the vehicle pseudonym, vehicle public key, message, and signature; if the verification equation is not valid, the message m is discarded. i If the verification equation holds true, then the message m is preliminarily determined. i If successful, a pseudonym query request is sent to the roadside unit closest to the onboard unit. The roadside unit then uses a smart contract to retrieve the vehicle's pseudonym (PID) from the revocation blockchain. i If no vehicle PID is found i If the vehicle authentication is successful, the system returns a result indicating that the vehicle pseudonym is valid. At this point, the on-board unit again verifies the validity of the message and receives the message m. i Otherwise, if a vehicle alias PID is found... i If the message fails to authenticate, the system returns a result indicating that the vehicle alias is invalid. In this case, the onboard unit again determines the message is invalid and discards it. i .

[0094] The verification equation is as follows:

[0095] σ i P = U i h i4 +h i3 (R i +h i1 P pub )+X i h i2 ;

[0096] Where, σ i U is the third parameter; P is the generator of the additive cyclic group; U i h is the second parameter. i4 The fourth hash value; h i3 The third hash value; R i For partial public keys; h i1 P is the first hash value; pub For the system public key; X i h is the first parameter. i2 This is the second hash value.

[0097] (3) Signature verification - Batch message authentication

[0098] In vehicle-to-everything (V2X) systems, a vehicle typically needs to verify n different messages simultaneously. Verifying each message individually is a very time-consuming process. Therefore, when a vehicle receives n different messages (PID1, PK1, m1, δ1, T1), ..., (PID... n PK n ,m n ,δ n ,T n When ), first use the timestamp T i Determine if the message is valid. If invalid, discard the message. Otherwise, check if the following formula is true.

[0099]

[0100] The performance of the blockchain-based certificateless identity authentication system in this embodiment is analyzed below:

[0101] (I) Security Analysis

[0102] Security analysis shows that this blockchain-based certificateless identity authentication system has high security and meets security requirements such as integrity, traceability, anonymity, and revocability. This is mainly due to the authenticationless signature scheme and the security of the blockchain, as described in detail below:

[0103] (1) Message integrity authentication: In this embodiment, it can be achieved by verifying σ i P = U i h i4 +hi3 (R i +h i1 P pub )+X i h i2 Whether it is true or false is used to ensure the validity and integrity of the message, σ i It is unforgeable in polynomial time because the Elliptic Curve Discrete Logarithm Problem (ECDLP) is a difficult problem. Therefore, this embodiment implements message integrity authentication.

[0104] (2) Decentralized key management: Combining certificateless cryptography and blockchain technology can effectively avoid the centralized security problems existing in traditional centralized systems and identity-based authentication schemes. Compared with existing authentication schemes based on blockchain and public key infrastructure, it has stronger security.

[0105] (3) Unlinkability: The signature generated by the same vehicle during the message signing stage is δ. i =(U i ,σ i ), because y i u i The vehicle alias and signature are generated randomly, meaning that the vehicle alias and signature change with the random number. Therefore, attackers cannot determine that two vehicle aliases come from the same vehicle, and the vehicle and the roadside unit cannot link two signatures sent by the same vehicle. Thus, this embodiment achieves the unlinkability of vehicles and messages.

[0106] (4) Traceability and revocability: In this embodiment, when a vehicle sends a false message or a traffic-related dispute occurs, the key generation center can retrieve the vehicle's real identity through the vehicle's pseudonym, thereby querying the vehicle's real identity and storing it in the revocation blockchain. Therefore, this embodiment achieves the traceability and revocability of the vehicle.

[0107] (5) Forward security and backward security: δ i =(U i ,σ i ) for vehicle to message m i The signature, where u is randomly selected each time the vehicle signs. i Therefore, even if an attacker obtains the current signature of the vehicle, they cannot deduce the vehicle's previous and next signatures. Thus, this embodiment achieves both forward and backward security for the vehicle.

[0108] (6) Resistance to impersonation attacks: Assuming that attacker A impersonates another legitimate vehicle to send a message, the message must satisfy the verification equation σ. i P = Ui h i4 +h i3 (R i +h i1 P pub )+X i h i2 Otherwise, the message is invalid. As can be seen from the difficulty of ECDLP, the signature generated by the vehicle is unforgeable. Therefore, this embodiment can resist impersonation attacks.

[0109] (7) Anti-tampering attack: In this embodiment, if the system master key is unknown, attacker A cannot calculate part of the vehicle's private key and cannot satisfy the verification equation. Therefore, attacker A cannot successfully tamper with the signature of the vehicle message. Thus, this embodiment can resist tampering attacks.

[0110] (8) Replay attack resistance: In this embodiment, a timestamp T is added to the message. i After receiving a message, the roadside unit or vehicle-mounted unit first checks whether the timestamp information is within the allowed time window. If the message timestamp T... i If the message is received within the allowed time window, the verifier will accept it; otherwise, the verifier will refuse to accept the message. Therefore, this embodiment can resist replay attacks.

[0111] (9) Resistance to joint attacks: In this embodiment, the key generation center first verifies whether the vehicle is legitimate through the vehicle management unit. If the verification is successful, the legitimate vehicle signs its message. Otherwise, the key generation center does not provide the vehicle's signature assistance. Even if some vehicle members sign the message together, they cannot generate the signature tracked by the key generation center. Therefore, this embodiment can resist joint attacks.

[0112] (10) Resistance to modification attacks: Assuming the attacker modifies message m i It will be discovered and discarded because it cannot forge m without the sender's private key. i The modified message / signature will return false upon verification. Therefore, this embodiment is resistant to modification attacks.

[0113] (II) Computational and Communication Performance Analysis

[0114] Simulation comparisons with existing solutions show that this embodiment has lower computational overhead and communication costs.

[0115] (1) Calculation cost

[0116] This embodiment uses the C / C++ cryptography library MIRACL to simulate and test the cryptographic operations of several existing schemes and the scheme designed in this embodiment. To ensure accuracy, each cryptographic operation is based on 1000 calculations, and the average value is taken as the final result, as shown in Table 1. Table 2 shows the computational cost of each scheme in the authentication process. This embodiment mainly calculates the computational cost of the signing and designing processes. In this embodiment, only one dot product operation on the elliptic curve (i.e., U) is performed during the signing process. i =u i P), the process of interpreting the divination requires performing 5 dot multiplication operations and 3 dot addition operations on the elliptic curve (i.e., σ). i P = U i h i4 +h i3 (R i +h i1 P pub )+X i h i2 ).

[0117] Table 1. Time consumed by different cryptographic operations

[0118] symbol meaning Time (ms) <![CDATA[T paec ]]> Time required for one elliptic curve addition operation 0.0021 <![CDATA[T smec ]]> Time required for one elliptic curve multiplication operation 0.4412 <![CDATA[T pbpa ]]> Time required for a single bilinear paired addition operation 0.0097 <![CDATA[T pbsm ]]> Time required for a single bilinear paired scalar multiplication operation 1.1003 <![CDATA[T bp ]]> Time required for one bilinear pairing operation 2.5521

[0119] Table 2 shows the computational cost of each scheme during the identity authentication process.

[0120] plan Signature overhead Validation overhead Total expenses Kamil scheme <![CDATA[3T smec +2T paec ]]> <![CDATA[4T smec +3T paec ]]> <![CDATA[7T smec +5T paec ]]> Gayathri scheme <![CDATA[2T smec ]]> <![CDATA[5T smec +3T pbpa ]]> <![CDATA[7T smec +3T pbpa ]]> Wang's Plan <![CDATA[4T smec +T paec ]]> <![CDATA[4T smec +T paec ]]> <![CDATA[8T smec +2T paec ]]> This embodiment's solution <![CDATA[T smec ]]> <![CDATA[5T smec +3T paec ]]> <![CDATA[6T smec +3T paec ]]>

[0121] In Table 2, the Kamil scheme refers to the improved certificateless aggregate signature scheme without bilinear pairings for vehicular ad hoc networks disclosed by Kamil IA et al. in the Journal of information security and applications; the Gayathri scheme refers to the efficient pairing-free certificateless authentication scheme with batch verification for vehicular ad-hoc networks disclosed by Gayathri NB et al. in IEEE Access; and the Wang scheme refers to the blockchain-based anonymous authentication with key management for smart gridedge computing infrastructure disclosed by Wang J et al. in IEEE Transactions on Industrial Informatics.

[0122] (2) Communication overhead

[0123] This embodiment constructs an additive cyclic group G based on points on the elliptic curve E and the point at infinity Θ. The group element size is 40 bytes, the timestamp size is 4 bytes, the hash value size is 20 bytes, and the integer field... The element size is 20 bytes. The communication overhead of each scheme during the identity authentication process is shown in Table 3. As can be seen from Table 3, the communication overhead of this embodiment is lower than other schemes. This is because this embodiment does not rely on bilinear pairing operations during the identity authentication process and uses fewer computational steps based on blockchain to complete the identity authentication process. Therefore, compared to other schemes, this embodiment requires a smaller message tuple size and relatively lower communication overhead. Comparative analysis reveals that this embodiment also has certain advantages in terms of communication overhead.

[0124] Table 3. Communication overhead of each scheme in the identity authentication process

[0125]

[0126]

[0127] (3) Communication delay

[0128] To better analyze the actual needs in the vehicle-to-everything (V2X) scenario, the communication modules of each scheme were simulated, and the actual communication latency of each scheme was obtained. The results are as follows: Figure 2 As shown, when the number of vehicles is 20, 40, 60, 80 and 100 respectively, the communication latency of different schemes is compared. In terms of communication latency, since the computational and communication overhead of this embodiment is lower than that of other schemes, a shorter communication latency will be generated.

[0129] Example 2

[0130] This embodiment provides a blockchain-based certificateless identity authentication method, applied to the blockchain-based certificateless identity authentication system described in Embodiment 1, such as... Figure 3 As shown, the blockchain-based certificateless identity authentication method includes:

[0131] S1: The on-board unit sends the vehicle's real identity to the key generation center and receives the vehicle's pseudonym returned by the key generation center.

[0132] S2: The vehicle unit generates the first parameter based on a random number and sends the vehicle pseudonym, message and the first parameter to the key generation center, and receives a partial key returned by the key generation center.

[0133] S3: The on-board unit generates the vehicle public key and vehicle private key based on the partial key.

[0134] S4: When a vehicle sends a message, the on-board unit generates a message signature based on the vehicle pseudonym, vehicle public key, and vehicle private key, and sends the vehicle pseudonym, vehicle public key, message, signature, and timestamp to other vehicles.

[0135] S5: When a vehicle receives a message, the on-board unit makes a preliminary judgment on whether the message is valid based on the vehicle pseudonym, vehicle public key, message, signature and timestamp. If the message is initially judged to be valid, it sends a pseudonym query request to the roadside unit, receives the judgment result of whether the vehicle pseudonym is valid returned by the roadside unit, and judges whether the message is valid again based on the judgment result. If the message is judged to be valid again, the message is received.

[0136] Example 3

[0137] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 4As shown, this computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs stored in the non-volatile storage media. The database is used for data exchange. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a blockchain-based certificateless authentication method.

[0138] Those skilled in the art will understand that Figure 4 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0139] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the blockchain-based certificateless identity authentication method of embodiment 2.

[0140] Example 4

[0141] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the blockchain-based certificateless identity authentication method of embodiment 2.

[0142] Example 5

[0143] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the blockchain-based certificateless identity authentication method of embodiment 2.

[0144] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0145] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0146] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A certificateless identity authentication system based on blockchain, characterized in that, The blockchain-based certificateless identity authentication system includes: an on-board unit, a roadside unit, and a key generation center. The on-board unit is communicatively connected to the roadside unit, and the roadside unit is communicatively connected to the key generation center. All roadside units and all key generation centers serve as blockchain nodes, forming a blockchain. The vehicle-mounted unit, installed on the vehicle, is used to send the vehicle's true identity to the key generation center; The key generation center is used to generate a vehicle pseudonym based on the vehicle's real identity, return the vehicle pseudonym to the vehicle unit, and store the vehicle's real identity and vehicle pseudonym in the blockchain; The vehicle-mounted unit is used to generate the first parameter based on a random number and send the vehicle pseudonym, message, and the first parameter to the key generation center. The key generation center is used to generate a partial key based on the vehicle pseudonym, the message, and the first parameter, and then returns the partial key to the vehicle unit. The on-board unit is used to generate the vehicle public key and vehicle private key based on partial keys; When a vehicle sends a message, the on-board unit generates a message signature based on the vehicle pseudonym, vehicle public key, and vehicle private key, and sends the vehicle pseudonym, vehicle public key, message, signature, and timestamp to other vehicles. When a vehicle receives a message, the on-board unit uses the vehicle pseudonym, vehicle public key, message, signature and timestamp to make a preliminary judgment on whether the message is valid. If the message is preliminarily judged to be valid, a pseudonym query request is sent to the roadside unit. The roadside unit is used to query the blockchain based on the pseudonym query request, determine whether the vehicle pseudonym is valid based on the query result, and return the determination result of whether the vehicle pseudonym is valid to the vehicle unit. The on-board unit is used to re-determine whether the message is valid based on the judgment result. If the message is valid again, the message is received.

2. The blockchain-based certificateless identity authentication system according to claim 1, characterized in that, The blockchain-based certificateless identity authentication system also includes: a motor vehicle management unit, which is communicatively connected to the on-board unit; The on-board unit is used to send a request to the vehicle management unit to obtain the true identity; The vehicle management unit is used to verify the vehicle's identity and return the vehicle's true identity to the on-board unit; The key generation center is used to verify the vehicle's true identity with the motor vehicle management unit after receiving the vehicle's true identity, and to generate a pseudonym for the vehicle based on the true identity after verification.

3. The blockchain-based certificateless identity authentication system according to claim 1 or 2, characterized in that, The formula for generating vehicle kana is: PID i =y i +sH0(RID i ||T i ); Among them, PID i For vehicle pseudonyms; y i s is the second random number; s is the first random number; H0 is the first hash function; RID i For the vehicle's true identity; T i For timestamps.

4. The blockchain-based certificateless identity authentication system according to claim 1, characterized in that, The formula for generating the first parameter is: X i =x i P; Among them, X i x is the first parameter; i is the third random number; P is the generator of the additive cyclic group; A partial key consists of a public key and a private key. The formula for generating a partial key is as follows: R i =r i P; Among them, R i For partial public keys; r i is the fourth random number; P is the generator of the additive cyclic group; d i =(r i +Sh i1 )mod q; Where, d i For partial private key; r i s is the fourth random number; s is the first random number; h i1 is the first hash value; mod is the modulo function; q is the order of the additive cyclic group; h i1 =H1(P pub ,PID i ,X i ,R i ); Among them, h i1 H1 is the first hash value; H1 is the second hash function; P pub For system public key; PID i For vehicle registration; X i R is the first parameter; i For a portion of the public key; The vehicle public key includes a first parameter and a portion of the public key, while the vehicle private key includes a third random number and a portion of the private key.

5. The blockchain-based certificateless identity authentication system according to claim 1, characterized in that, The signature includes a second parameter and a third parameter, and the formula for generating the signature is: IN i =in i P; Among them, U i The second parameter; u i is the fifth random number; P is the generator of the additive cyclic group; σ i =h i4 you i +h i3 d i +h i2 x i ; Where, σ i h is the third parameter. i4 The fourth hash value; u i The fifth random number; h i3 The third hash value; d i For partial private key; h i2 The second hash value; x i The third random number; h i4 =H4(PID i ,PK i ,m i ,U i ); Among them, h i4 H4 is the fourth hash value; H4 is the fifth hash function; PID i For vehicle pseudonyms; PK i For vehicle public key; m i For message; U i The second parameter; h i3 =H3(PID i ,R i ,m i ,U i ); Among them, h i3 H3 is the third hash value; H3 is the fourth hash function; PID i For vehicle names; R i For partial public keys; m i For message; U i This is the second parameter; h i2 =H2(PID i ,X i ,m i ,U i ); Among them, h i2 H2 is the second hash value; H2 is the third hash function; PID i For vehicle registration; X i m is the first parameter; i For message; U i This is the second parameter.

6. The blockchain-based certificateless identity authentication system according to claim 1, characterized in that, The vehicle unit is used to determine whether the difference between the time of receiving the message and the timestamp is less than a preset difference. If so, it determines whether the verification equation is true based on the vehicle pseudonym, vehicle public key, message and signature. If true, it initially determines that the message is valid. The verification equation is as follows: σ i P=U i h i4 +h i3 (R i +h i1 P pub )+X i h i2 ; Where, σ i U is the third parameter; P is the generator of the additive cyclic group; U i h is the second parameter. i4 The fourth hash value; h i3 The third hash value; R i For partial public keys; h i1 P is the first hash value; pub For the system public key; X i h is the first parameter; i2 This is the second hash value.

7. The blockchain-based certificateless identity authentication system according to claim 1, characterized in that, The blockchain includes a pseudonym blockchain and a revocation blockchain. The pseudonym blockchain stores valid vehicle pseudonyms and the vehicle's real identity, while the revocation blockchain stores invalid vehicle pseudonyms.

8. A blockchain-based certificateless identity authentication method, applied to any one of the blockchain-based certificateless identity authentication systems described in claims 1-7, characterized in that, The blockchain-based certificateless identity authentication method includes: The vehicle unit sends the vehicle's real identity to the key generation center and receives the vehicle's pseudonym returned by the key generation center; The vehicle unit generates the first parameter based on a random number and sends the vehicle pseudonym, message and the first parameter to the key generation center, and receives a partial key returned by the key generation center. The on-board unit generates a vehicle public key and a vehicle private key based on a partial key; When a vehicle sends a message, the on-board unit generates a message signature based on the vehicle pseudonym, vehicle public key, and vehicle private key, and sends the vehicle pseudonym, vehicle public key, message, signature, and timestamp to other vehicles. When a vehicle receives a message, the on-board unit makes a preliminary judgment on the validity of the message based on the vehicle pseudonym, vehicle public key, message, signature, and timestamp. If the message is initially determined to be valid, it sends a pseudonym query request to the roadside unit and receives the judgment result on the validity of the vehicle pseudonym returned by the roadside unit. Based on the judgment result, it makes another judgment on the validity of the message. If the message is determined to be valid again, it receives the message.

9. A computer device, comprising: A memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that the processor executes the computer program to implement the blockchain-based certificateless identity authentication method of claim 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the blockchain-based certificateless identity authentication method as described in claim 8.

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