Certificateless identity authentication method based on block chain and related device

Abstract

The invention discloses a blockchain-based certificateless identity authentication method and a related device, and relates to the technical field of Internet of Vehicles, the system comprises an on-board unit, road side units and a key generation center, all road side units and all key generation centers serve as blockchain nodes to form a blockchain, the on-board unit communicates with the key generation center, and the key generation center is used for generating key information. And a vehicle pseudonym, a vehicle public key and a vehicle private key are generated, and a subsequent on-board unit completes message sending and receiving based on the vehicle pseudonym, the vehicle public key and the vehicle private key and communicates with other vehicles. In the process, the real identity of the vehicle and the pseudonym of the vehicle are stored in the block chain and inquired in the block chain, the real identity of the vehicle and the pseudonym of the vehicle are stored in the block chain by introducing the block chain, and the real identity of the vehicle and the pseudonym of the vehicle are stored in the block chain by means of the characteristics of distribution, traceability, non-tampering and the like of the block chain. The security of certificateless identity authentication can be improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle networking technology, and in particular to a certificateless identity authentication method and related devices based on blockchain. Background Art

[0002] The Internet of Vehicles (IoV) is an application of the Internet of Things in the field of transportation, which aims to improve traffic efficiency. It is based on the onboard unit (OBU) installed on the vehicle, effectively promoting the dissemination of real-time traffic information, and has become a key technology to alleviate traffic problems. In actual traffic scenarios, vehicles can obtain safety-related traffic information in real time through the IoV, such as the speed, direction and dangerous road conditions of surrounding vehicles, thereby improving driving experience and driving safety. There are three main communication modes in a typical IoV, namely wired / wireless connection, vehicle-to-vehicle and vehicle-to-road side unit (RSU). Wired / wireless connection is used to connect vehicles or road side units to the Internet. Vehicle-to-vehicle and vehicle-to-road side unit are controlled by the Dedicated Short Range Communications (DSRC) protocol through the IEEE 802.11p standard to facilitate close-range communication.

[0003] The Internet of Vehicles and the Internet of Things have some common characteristics, but also some particularities. Both the Internet of Vehicles and the Internet of Things rely on device interconnection and data exchange to achieve intelligent management and operation. However, the Internet of Vehicles has its own particularities, including high-speed mobility of vehicles, dynamic changes in network topology, high real-time requirements, and stricter security and privacy protection requirements. These particularities make the Internet of Vehicles face unique challenges in data transmission reliability, low-latency communication and security. Therefore, although the Internet of Vehicles has many advantages, more attention should be paid to the security challenges in the process of information sharing between vehicles. Due to the openness of the wireless communication channel in the Internet of Vehicles, the wireless communication channel may be destroyed and controlled by malicious attackers, and the data information transmitted in the wireless communication channel may be eavesdropped and modified.

[0004] In the Internet of Vehicles, vehicles broadcast messages containing vehicle identity information to communicate with other vehicles or infrastructure. Attackers can decrypt the identity information by stealing the private information of the sender's vehicle, thereby threatening the life and property safety of vehicle users. Although authentication is one of the effective means to solve the communication security problem, in the traditional centralized system, the private information of the vehicle is centrally stored. Therefore, once the centralized system is invaded, the private information of the sender's vehicle will be completely leaked, which will bring serious data and user privacy security risks, and communication security will no longer be guaranteed. At the same time, with the rapid development of the Internet of Vehicles, a large number of vehicle nodes are connected to this huge network, which brings huge challenges to the big data storage, intelligent management and information security of the entire Internet of Vehicles system. The traditional centralized data processing method and centralized network architecture can no longer meet the high security, high reliability and real-time response requirements of Internet of Vehicles data sharing. Therefore, studying new Internet of Vehicles security architecture and efficient and secure authentication schemes has important research value and significance for ensuring communication security and providing drivers with a comfortable driving environment.

[0005] For an open Internet of Vehicles environment, authentication plays a great role in improving communication security and avoiding security threats. Existing authentication schemes mainly include: authentication schemes based on Public Key Infrastructure (PKI), authentication schemes based on identity, and authentication schemes based on certificateless signatures. However, authentication schemes based on public key infrastructure have the problem that it is difficult for vehicles to manage and store a large number of public and private key pairs and related certificates. Identity-based authentication schemes are where the Key Generation Center (KGC) uses its own master key to generate a key for an on-board entity. It cannot ensure non-repudiation because the KGC can abuse the vehicle's access capabilities to sign and decrypt any message, leading to key escrow issues. Compared with the authentication scheme based on public key infrastructure and the authentication scheme based on identity, the authentication scheme based on certificateless signature has many advantages. Unlike the authentication scheme based on public key infrastructure, the authentication scheme based on certificateless signature does not require any certificate to ensure the validity of the public key. Therefore, the absence of certificates can reduce communication, computing and storage overheads. Unlike the identity-based authentication scheme, the KGC in the authentication scheme based on certificateless signature is a semi-trusted authority, which calculates part of the private key based on the user's identity and provides it to the user. The actual private key is calculated using the secret value and the part of the private key. The KGC does not have any authority to access the user's private key, so there is no key escrow problem.

[0006] However, in the authentication scheme based on certificateless signature, the traditional centralized system is still used. At this time, the private information of the vehicle is stored centrally. Therefore, once the centralized system is invaded, the private information of the sender's vehicle 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 certificateless 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 devices, which can improve the security of certificateless identity authentication.

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

[0009] In a first aspect, the present application provides a certificateless identity authentication system based on blockchain, the certificateless identity authentication system based on blockchain comprising: 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 to form a blockchain;

[0010] The on-board unit is installed on the vehicle and is used to send the real identity of the vehicle 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 on-board unit, and store the vehicle's real identity and vehicle pseudonym in the blockchain;

[0012] The on-board unit is used to generate a first parameter based on a random number, and send the vehicle pseudonym, the 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 return the partial key to the on-board unit;

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

[0015] When the vehicle sends a message, the on-board unit is used to generate a signature of the message based on the vehicle pseudonym, the vehicle public key and the vehicle private key, and send the vehicle pseudonym, the vehicle public key, the message, the signature and the timestamp to other vehicles;

[0016] When the vehicle receives the message, the onboard unit is used to preliminarily determine whether the message is valid based on the vehicle pseudonym, vehicle public key, message, signature and timestamp, and if the message is preliminarily determined 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 on-board unit;

[0018] The on-board unit is used to determine again whether the message is valid based on the determination result, and if the message is determined to be valid again, the message is received.

[0019] In a second aspect, the present application provides a blockchain-based certificateless identity authentication method, which is applied to the above-mentioned blockchain-based certificateless identity authentication system, and the blockchain-based certificateless identity authentication method includes:

[0020] The vehicle-mounted unit sends the real identity of the vehicle to the key generation center, and receives the pseudonym of the vehicle returned by the key generation center;

[0021] The on-board unit generates a first parameter based on a random number, sends a vehicle pseudonym, a message and the first parameter to a 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 the partial key;

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

[0024] When the vehicle receives a message, the on-board unit preliminarily determines whether the message is valid based on the vehicle pseudonym, vehicle public key, message, signature and timestamp. If the message is preliminarily determined to be valid, a pseudonym query request is sent to the roadside unit, and a judgment result of whether the vehicle pseudonym is valid is received from the roadside unit. Based on the judgment result, the message is again determined to be valid. If the message is again determined to be valid, the message is received.

[0025] In a third aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-mentioned blockchain-based certificateless identity authentication method.

[0026] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned blockchain-based certificateless identity authentication method.

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

[0028] The present application provides a certificateless identity authentication method and related devices based on blockchain, including: an on-board unit, a roadside unit and a key generation center, all roadside units and all key generation centers serve as blockchain nodes to form a blockchain, the on-board unit sends the real identity of the vehicle to the key generation center, the key generation center generates a vehicle pseudonym based on the real identity of the vehicle, returns the vehicle pseudonym to the on-board unit, and stores the real identity of the vehicle and the 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, and 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 generates a signature for the message 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 preliminarily determines whether the message is valid based on the vehicle pseudonym, vehicle public key, message, signature, and timestamp. If the message is preliminarily determined to be valid, a pseudonym query request is sent to the roadside unit. The roadside unit queries the blockchain based on the pseudonym query request, determines whether the vehicle pseudonym is valid based on the query result, and returns the determination result of whether the vehicle pseudonym is valid to the on-board unit. The on-board unit determines whether the message is valid again based on the determination result. If the message is determined to be valid again, the message is received. This application introduces a blockchain to store the vehicle's real identity and vehicle pseudonym in the blockchain. With the distributed, traceable, and tamper-proof characteristics of the blockchain, the security of certificateless identity authentication can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A connection diagram of a blockchain-based certificateless identity authentication system provided in Example 1 of the present application.

[0031] Figure 2 A schematic diagram comparing the communication delays of different schemes provided in Example 1 of the present application.

[0032] Figure 3 A method flow chart of a blockchain-based certificateless identity authentication method provided in Example 2 of the present application.

[0033] Figure 4A schematic diagram of the structure of a computer device provided in Example 3 of the present application. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] Example 1

[0036] At present, the authentication scheme based on certificateless signature still adopts the traditional centralized system, which has the problem of insecurity, and uses bilinear mapping operation, resulting in low computational efficiency. Therefore, the existing authentication scheme based on certificateless signature solves the security and privacy problems in the Internet of Vehicles to a certain extent, but still faces the problems of large amount of data storage, real-time processing response, user privacy security and other problems brought by the traditional centralized system. How to design a safer and more efficient certificateless identity authentication scheme is still a hot issue. Blockchain is an effective distributed storage and security management technology with the characteristics of decentralization, openness and transparency. With the help of the distributed, secure, traceable and tamper-proof characteristics of blockchain technology, the application of blockchain technology to the Internet of Vehicles can enable vehicles to use decentralized systems for information transmission, improve the trust between different entities, and provide a reliable environment for information sharing between vehicles, which is more secure than the traditional centralized system. Blockchain technology can protect data from being tampered with, and multiple entities jointly maintain the same account information. Information sharing can reduce the burden of centralized entities and provide an effective channel to solve the security risks of traditional centralized systems. Therefore, in the insecure and unstable communication links of the Internet of Vehicles, studying efficient and secure blockchain-based certificateless authentication schemes has high theoretical significance and practical application value.

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

[0038] The on-board unit is installed on the vehicle and 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 the vehicle pseudonym in the blockchain.

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

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

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

[0044] When the vehicle receives a message, the on-board unit is used to preliminarily determine whether the message is valid based on the vehicle pseudonym, vehicle public key, message, signature and timestamp. 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 judgment result of whether the vehicle pseudonym is valid to the on-board unit.

[0046] The on-board unit is used to determine again whether the message is valid based on the determination result, and if the message is determined to be valid again, the message is received.

[0047] In order to ensure that the real identity of the vehicle sent by the on-board unit is indeed the real identity of the vehicle, and not a forged identity of the vehicle, the blockchain-based certificateless identity authentication system of this embodiment also includes: a motor vehicle management unit, which is communicatively connected with the on-board unit.

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

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

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

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

[0052] Based on the communication structure of the Internet of Vehicles, this embodiment introduces a key generation center as an institution to assist vehicles in generating vehicle public keys and vehicle private keys, introduces a motor vehicle management unit (MVD for short) as an institution to verify vehicle identities, and introduces a blockchain. The blockchain nodes include a key generation center and a roadside unit, such as Figure 1 As shown, at this time, the certificateless identity authentication system based on blockchain of this embodiment includes: a key generation center, a roadside unit, a vehicle-mounted unit, a motor vehicle management unit and a blockchain, wherein the key generation center and the roadside unit perform wired communication through a secure channel, the roadside unit and the vehicle-mounted unit perform V2R (Vehicle to Roadside Unit) communication through a dedicated short-range communication protocol, the vehicle-mounted units perform V2V (Vehicle to Vehicle) communication through a dedicated short-range communication protocol, and the vehicle-mounted units and the motor vehicle management unit perform wired communication.

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

[0054] (1) Key Generation Center: The key generation center plays the role of a management center in the Internet of Vehicles system. In the Internet of Vehicles authentication scheme, the key generation center is mainly responsible for the registration of roadside units and vehicle-mounted units, identity authentication, generation of system master keys, and publication of system parameters. The key generation center is the only entity in the Internet of Vehicles system that can reveal the true identity of the vehicle and can retrieve and decrypt the true identity information of the vehicle in 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 provide real-time feedback to vehicles on traffic information such as road conditions and weather information in the area. The roadside unit has stronger computing capabilities.

[0056] (3) On-board unit: The on-board unit is a physical unit installed in the vehicle and has certain computing capabilities. It can actively or passively provide communication services for the vehicle. Each registered on-board unit is equipped with a tamper-proof device (TPD) to store key values ​​or other data. The on-board unit can connect to the surrounding wireless network through its own wireless communication components to transmit information, so that the vehicle can transmit messages with other surrounding vehicles or roadside units.

[0057] (4) Motor vehicle management unit: It can be the motor vehicle management department that assigns a unique corresponding real identity ID to the vehicle before the vehicle enters the Internet of Vehicles system.

[0058] (5) Blockchain: A decentralized underlying architecture is constructed using blockchain. The key generation center and roadside unit are selected as blockchain nodes, and some blockchain nodes are selected as consensus nodes. For example, the key generation center is selected as the consensus node. The consensus node executes the PBFT (Practical Byzantine Fault Tolerance) consensus algorithm to complete the blockchain initialization. Two blockchains are used in the Internet of Vehicles system to store different data. One blockchain is used to store the real identity of the vehicle encrypted by the vehicle user, the generated vehicle pseudonym and the corresponding vehicle public key, which can be called the pseudonym blockchain. The other blockchain is used to store the vehicle pseudonym that has been revoked after verification, which can be called the revocation blockchain.

[0059] The blockchain in this embodiment may be a consortium chain.

[0060] The following is an introduction to the working process of the blockchain-based certificateless identity authentication system of this embodiment:

[0061] (1) 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 prime number q, where q is a large prime number, q>2k, k is an input security parameter, and the generator of the additive cyclic group G is denoted by P.

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

[0064] (3) The key generation center selects five collision-resistant hash functions: Among them, 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 As the system master key, and calculate the system public key P 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 publishes system parameters Params = {G, q, P, P pub , H0, H1, H2, H3, H4}, and secretly save the first random number s.

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

[0068] (2) Vehicle initialization and registration.

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

[0070] (2) The vehicle-mounted unit sends the vehicle’s real identity RID i The key generation center can verify the real identity of the registered vehicle by communicating with the motor vehicle management unit. If the real identity of the vehicle exists (i.e., the 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 use the vehicle pseudonym RID i Return to the vehicle unit. At the same time, the key generation center sends the vehicle's pseudonym PID i With the vehicle's real identity RID i Stored on the pseudonymous blockchain. Among them, PID i is the vehicle pseudonym, which is the unique identity generated by the key generation center for the vehicle, y i is the second random number, s is the first random number, H0 is the first hash function, RID i is the real identity of the vehicle, T i Is the timestamp.

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

[0072] (3) The on-board unit randomly selects a third random number As a secret value, calculate the first parameter X i =x i P, and (PID i ,mi ,X i ) is sent to the key generation center. Among them, X i is the first parameter, x i is the third random number, P is the generator of the additive cyclic group, m i For news.

[0073] (4) The key generation center receives the (PID i ,m i ,X i ) and then randomly select a fourth random number First calculate the partial public key R i =r i P and the first hash value h i1 =H1(P pub ,PID i ,X i ,R i ), and then calculate the partial private key d i =(r i +sh i1 ) mod q, and the calculated partial key (d i ,R i ) is sent to the corresponding vehicle-mounted unit. i is a partial public key, r i is the fourth random number, P is the generator of the additive cyclic group, h i1 is the first hash value, H1 is the second hash function, P pub Is the system public key, PID i The vehicle name is X. i is the first parameter, d i is the partial private key, s is the first random number, mod is the remainder function, and q is the order of the additive cyclic group.

[0074] (5) The on-board unit receives the partial key (d i ,R i ) and verify d i P=R i +h i1 P pub Is it true? If so, receive the partial key and continue execution, otherwise terminate execution. i is a partial private key, P is the generator of the additive cyclic group, R i is part of the public key, h i1 is the first hash value, P pub The system public key.

[0075] (6) The vehicle-mounted unit sets its own vehicle public key PK i =(X i ,Ri ) and the vehicle private key SK i =(x i ,d i ). Among them, PK i is the vehicle public key, X i is the first parameter, R i is the partial public key, SK i is the vehicle private key, x i is the third random number, d i Part of the private key.

[0076] (3) Vehicle certification.

[0077] During the vehicle authentication process, in order to ensure the authenticity and integrity of the message, the vehicle must sign the message it sends and decrypt the message it receives. Specifically, the vehicle's on-board unit uses the vehicle's pseudonym PID to authenticate the vehicle. i , using the vehicle public key PK i and the 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 signature for the message 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. At this time, the onboard unit randomly selects a fifth random number. Then the message m i Perform signature calculation. The signature generation formula is:

[0080] U i =u i P;

[0081] Among them, U i is 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] Among them, σ i is the third parameter; h i4 is the fourth hash value; u i is the fifth random number; h i3 is the third hash value; d i is part of the private key; h i2 is the second hash value; xi is the third random number.

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

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

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

[0087] Among them, h i3 is the third hash value; H3 is the fourth hash function; PID i R is a pseudonym for the vehicle; i is part of the public key; m i For news; i is the second parameter.

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

[0089] Among them, h i2 is the second hash value; H2 is the third hash function; PID i This is a pseudonym for the vehicle; X i is the first parameter; m i For news; i is the second parameter.

[0090] The vehicle-mounted unit will i =(U i ,σ i ) as a response to message m i Signature and send (PID i ,PK i ,m i ,δ i ,T i ) to other vehicles that need to communicate. Among them, PID i This is a pseudonym for the vehicle, PK i is the vehicle public key, mi is the message, δ i For signature, T i Is the timestamp.

[0091] (2) Signature Verification - Single Vehicle Message Authentication

[0092] When the vehicle receives a message, the onboard unit preliminarily determines whether the message is valid based on the vehicle pseudonym, vehicle public key, message, signature and timestamp. If the message is preliminarily determined to be valid, a pseudonym query request is sent to the roadside unit. The roadside unit queries the blockchain based on the pseudonym query request, determines whether the vehicle pseudonym is valid based on the query result, and returns the determination result of whether the vehicle pseudonym is valid to the onboard unit. The onboard unit determines whether the message is valid again based on the determination result. If the message is determined to be valid again, the message is received.

[0093] At this time, the vehicle-mounted unit receives the (PID i ,PK i ,m i ,δ i ,T i ) to verify the message m i The validity and legitimacy of the vehicle identity. First, through the timestamp T i Judge message m i Whether it is valid, specifically determine whether the difference between the time of receiving the message and the timestamp is less than the preset difference. If so, the message m i Valid, if not, then message m i Invalid; if the message m i If invalid, the message will be discarded directly. i Otherwise, if the message m i If the verification equation is valid, the vehicle pseudonym, vehicle public key, message and signature are used to determine whether the verification equation is valid; if the verification equation is not valid, the message m is directly discarded. i ; If the verification equation holds, the message m is preliminarily determined i Valid, send a pseudonym query request to the roadside unit closest to the vehicle unit, and the roadside unit uses the smart contract to retrieve the vehicle pseudonym PID in the revocation blockchain i If the vehicle pseudonym PID is not found i , then the result of vehicle authentication is returned, that is, the vehicle pseudonym is valid. At this time, the on-board unit determines that the message is valid again and receives the message m i Otherwise, if the vehicle pseudonym PID is found i , then the result of vehicle authentication failure is returned, that is, the vehicle pseudonym is invalid. At this time, the on-board unit again determines that the message is invalid and directly discards the message m i .

[0094] The verification equation is:

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

[0096] Among them, σ i is the third parameter; P is the generator of the additive cyclic group; U i is the second parameter; h i4 is the fourth hash value; i3 is the third hash value; R i is part of the public key; h i1 is the first hash value; P pub is the system public key; X i is the first parameter; h i2 is the second hash value.

[0097] (3) Signature Verification - Batch Message Authentication

[0098] In the Internet of Vehicles system, vehicles usually need to verify n different messages at the same time. Verifying each message one by one 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 ), firstly through the timestamp T i Determine whether the message is valid. If not, discard the message directly. Otherwise, determine whether the following formula holds.

[0099]

[0100] The following is an analysis of the performance of the blockchain-based certificateless identity authentication system of this embodiment:

[0101] 1. Security Analysis

[0102] Security analysis shows that the blockchain-based certificateless identity authentication system is highly secure and meets security requirements such as integrity, traceability, anonymity, and revocability. This is mainly based on the security of the non-authenticated signature scheme and blockchain, as described below:

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

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

[0105] (3) Unlinkability: The same vehicle generates a signature of δ in the message signing phase. i =(U i ,σ i ), due to y i ,u i It is randomly generated, that is, the vehicle pseudonym and signature of the vehicle change with the change of the random number. Therefore, an attacker cannot determine that two vehicle pseudonyms come from the same vehicle, and the vehicle and the roadside unit cannot link the two signatures sent by the same vehicle. Therefore, this embodiment realizes the unlinkability of the vehicle and the message.

[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 real identity of the vehicle through the vehicle pseudonym, and then query the real identity of the vehicle and store it in the revocation blockchain. Therefore, this embodiment realizes the traceability and revocability of the vehicle.

[0107] (5) Forward security and backward security: δ i =(U i ,σ i ) is the vehicle response message m i The vehicle randomly selects u each time it signs. i Therefore, even if an attacker obtains the current signature of the vehicle, he cannot infer the front and rear signatures of the vehicle. Therefore, this embodiment realizes the forward security and backward security of the vehicle.

[0108] (6) Anti-counterfeiting attack: Assume that attacker A pretends to be another legitimate vehicle to send a message, and 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. From the difficulty of ECDLP, it can be seen that the signature generated by the vehicle is unforgeable. Therefore, this embodiment can resist counterfeit attacks.

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

[0110] (8) Anti-replay attack: In this embodiment, a timestamp T is added to the message. i After receiving the message, the RSU or OMU first checks whether the time information of the timestamp is within the allowed time window. If the message timestamp T i If the message is within the allowed time window, the verifier receives the message; otherwise, the verifier refuses to receive 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 legal through the motor vehicle management unit. If the verification is successful, the legal vehicle signs its message. Otherwise, the key generation center does not provide signing assistance for the vehicle. Even if some vehicle members jointly sign the message, they cannot generate a signature that the key generation center tracks. Therefore, this embodiment can resist joint attacks.

[0112] (10) Anti-modification attack: Assume that the attacker modifies the message m i , it will be discovered and discarded because without the sender's private key, it cannot forge m i , and the verification of the modified message / signature will return false. Therefore, this embodiment can resist modification attacks.

[0113] 2. Computation and communication performance analysis

[0114] Simulation comparison with existing solutions shows that this embodiment has lower computing overhead and communication cost.

[0115] (1) Calculation overhead

[0116] This embodiment uses the C / C++ cryptography library MIRACL to simulate and test the cryptographic operations of several existing schemes and the scheme of this embodiment. Considering the accuracy of the test, 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 overhead of each scheme in the identity authentication process. This embodiment mainly counts the computational overhead of the signing process and the decryption process. In the signing process, this embodiment only needs to perform one point multiplication operation on the elliptic curve (i.e., U i =u i P), during the decryption process, five point multiplication operations on the elliptic curve and three point addition operations on the elliptic curve need to be performed (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 consumption of different cryptographic operations

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

[0119] Table 2 Computational overhead of each scheme in the identity authentication process

[0120] plan Signature Overhead Authentication overhead Total expenses Kamil Solution <h2 style=";text-align:left;direction:ltr"><![CDATA[3T <h2 style=";text-align:left;direction:ltr"> smec <h2 style=";text-align:left;direction:ltr"> +2T<h2 style=";text-align:left;direction:ltr"> paec <h2 style=";text-align:left;direction:ltr"> ]]><h2 style=";text-align:left;direction:ltr"> <![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 Solution <![CDATA[4T smec +T paec ]]> <![CDATA[4T smec +T paec ]]> <h2 style=";text-align:left;direction:ltr"><![CDATA[8T <h2 style=";text-align:left;direction:ltr"> smec <h2 style=";text-align:left;direction:ltr"> +2T<h2 style=";text-align:left;direction:ltr"> paec <h2 style=";text-align:left;direction:ltr"> ]]><h2 style=";text-align:left;direction:ltr"> This embodiment scheme <![CDATA[T smec ]]> <![CDATA[5T smec +3T paec ]]> <![CDATA[6T smec +3T paec ]]>

[0121] In Table 2, Kamil scheme refers to An improved certificateless aggregate signature scheme without bilinear pairings for vehicular ad hoc networks published by Kamil IA et al. in Journal of information security and applications, Gayathri scheme refers to Efficient pairing-free certificateless authentication scheme with batch verification for vehicular ad-hoc networks published by Gayathri N B et al. in IEEE Access, and Wang scheme refers to Blockchain-based anonymous authentication with key management for smart grid edge computing infrastructure published 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 the points on the elliptic curve E and the point Θ at infinity. The size of the group element is 40 bytes, the size of the timestamp is 4 bytes, the size of the hash value is 20 bytes, and the integer domain is The element size in is 20 bytes. The communication overhead of each scheme in the identity authentication process is shown in Table 3 below. It can be seen from Table 3 that the communication overhead of the scheme in this embodiment is lower than that of other schemes. This is because the scheme in this embodiment does not rely on bilinear pairing operations in the identity authentication process, and uses fewer computing steps based on blockchain to complete the identity authentication process. Therefore, compared with other schemes, the message tuples that need to be transmitted in this embodiment are smaller in size, and the communication overhead is relatively small. Through comparative analysis, it can be found that the scheme in 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] In order to better analyze the actual needs of the Internet of Vehicles scenario, the communication modules of each solution were simulated and the actual communication delay of each solution 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 delays of different schemes are compared. In terms of communication delay, since the computational overhead and communication overhead of this embodiment are lower than those of other schemes, a shorter communication delay will be generated.

[0129] Example 2

[0130] This embodiment provides a certificateless identity authentication method based on blockchain, which is applied to the certificateless identity authentication system based on blockchain described in Example 1. Figure 3 As shown, the certificateless identity authentication method based on blockchain includes:

[0131] S1: The vehicle-mounted unit sends the real identity of the vehicle to the key generation center and receives the vehicle pseudonym returned by the key generation center.

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

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

[0134] S4: When the vehicle sends a message, the on-board unit generates a signature of the message 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 the vehicle receives a message, the on-board unit preliminarily determines whether the message is valid based on the vehicle pseudonym, vehicle public key, message, signature and timestamp. If the message is preliminarily determined to be valid, a pseudonym query request is sent to the roadside unit, and a judgment result of whether the vehicle pseudonym is valid is received from the roadside unit. Based on the judgment result, the message is again determined to be valid. If the message is again determined to be valid, the message is received.

[0136] Example 3

[0137] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 4As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used for data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a certificateless identity authentication method based on blockchain is implemented.

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

[0139] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the blockchain-based certificateless identity authentication method in Example 2 is implemented.

[0140] Example 4

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

[0142] Example 5

[0143] In an exemplary embodiment, a computer program product is provided, including a computer program, which, when executed by a processor, implements the blockchain-based certificateless identity authentication method in Example 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, stored data, displayed data, 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 relevant data must comply with relevant regulations.

[0145] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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 article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A certificateless identity authentication system based on blockchain, characterized in that: The certificateless identity authentication system based on blockchain includes: an on-board unit, a roadside unit and a key generation center, the on-board unit is in communication connection with the roadside unit, and the roadside unit is in communication connection with the key generation center; all roadside units and all key generation centers serve as blockchain nodes to form a blockchain; The on-board unit is installed on the vehicle and is used to send the real identity of the vehicle 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 on-board unit, and store the vehicle's real identity and vehicle pseudonym in the blockchain; The on-board unit is used to generate a first parameter based on a random number, and send the vehicle pseudonym, the 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 return the partial key to the on-board unit; The on-board unit is used to generate a vehicle public key and a vehicle private key based on the partial key; When the vehicle sends a message, the on-board unit is used to generate a signature of the message based on the vehicle pseudonym, the vehicle public key and the vehicle private key, and send the vehicle pseudonym, the vehicle public key, the message, the signature and the timestamp to other vehicles; When the vehicle receives the message, the onboard unit is used to preliminarily determine whether the message is valid based on the vehicle pseudonym, vehicle public key, message, signature and timestamp, and if the message is preliminarily determined 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 on-board unit; The on-board unit is used to determine again whether the message is valid based on the determination result, and if the message is determined to be valid again, the message is received.

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

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

4. The certificateless identity authentication system based on blockchain according to claim 1 is characterized in that: The formula for generating the first parameter is: X i =x i P; Among them, X i is the first parameter; x i is the third random number; P is the generator of the additive cyclic group; The partial key includes a partial public key and a partial private key. The generation formula of the partial key is: R i =r i P; Among them, R i is a partial public key; r i is the fourth random number; P is the generator of the additive cyclic group; d i =(r i +Sh i1 )mod q; Among them, d i is a partial private key; r i is the fourth random number; s is the first random number; h i1 is the first hash value; mod is the remainder 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 is the first hash value; H1 is the second hash function; P pub Is the system public key; PID i This is a pseudonym for the vehicle; X i is the first parameter; R i is a partial public key; The vehicle public key includes a first parameter and a partial public key, and the vehicle private key includes a third random number and a partial private key.

5. The certificateless identity authentication system based on blockchain according to claim 1, characterized in that: The signature includes the second parameter and the third parameter. The signature generation formula is: IN i =in i P; Among them, U i is 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 ; Among them, σ i is the third parameter; h i4 is the fourth hash value; u i is the fifth random number; h i3 is the third hash value; d i is part of the private key; h i2 is the second hash value; x i is the third random number; h i4 =H4(PID i ,PK i ,m i ,U i ); Among them, h i4 is the fourth hash value; H4 is the fifth hash function; PID i Pseudonym for the vehicle; PK i is the vehicle public key; m i For news; i is the second parameter; h i3 =H3(PID i ,R i ,m i ,U i ); Among them, h i3 is the third hash value; H3 is the fourth hash function; PID i R is a pseudonym for the vehicle; i is part of the public key; m i For news; i is the second parameter; h i2 =H2(PID i ,X i ,m i ,U i ); Among them, h i2 is the second hash value; H2 is the third hash function; PID i This is a pseudonym for the vehicle; X i is the first parameter; m i For news; i is the second parameter.

6. The certificateless identity authentication system based on blockchain according to claim 1, characterized in that: The on-board 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 established based on the vehicle pseudonym, vehicle public key, message and signature. If so, it preliminarily determines that the message is valid; The verification equation is: σ i P=U i h i4 +h i3 (R i +h i1 P pub )+X i h i2 ; Among them, σ i is the third parameter; P is the generator of the additive cyclic group; U i is the second parameter; h i4 is the fourth hash value; i3 is the third hash value; R i is part of the public key; h i1 is the first hash value; P pub is the system public key; X i is the first parameter; h i2 is the second hash value.

7. The certificateless identity authentication system based on blockchain 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 real vehicle identities, and the revocation blockchain stores invalid vehicle pseudonyms.

8. A certificateless identity authentication method based on blockchain, applied to the certificateless identity authentication system based on blockchain as described in any one of claims 1 to 7, characterized in that: The blockchain-based certificateless identity authentication method includes: The vehicle-mounted unit sends the real identity of the vehicle to the key generation center, and receives the pseudonym of the vehicle returned by the key generation center; The on-board unit generates a first parameter based on a random number, sends a vehicle pseudonym, a message and the first parameter to a 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 the partial key; When a vehicle sends a message, the on-board unit generates a signature of the message based on the vehicle pseudonym, the vehicle public key and the vehicle private key, and sends the vehicle pseudonym, the vehicle public key, the message, the signature and the timestamp to other vehicles; When the vehicle receives a message, the on-board unit preliminarily determines whether the message is valid based on the vehicle pseudonym, vehicle public key, message, signature and timestamp. If the message is preliminarily determined to be valid, a pseudonym query request is sent to the roadside unit, and a judgment result of whether the vehicle pseudonym is valid is received from the roadside unit. Based on the judgment result, the message is again determined to be valid. If the message is again determined to be valid, the message is received.

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

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

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