Safe and low-delay batch authentication method for block chain vehicle-mounted self-organizing network

Abstract

The invention discloses a safe and low-delay batch authentication method for a block chain vehicle-mounted self-organizing network, belongs to the technical field of information security, and aims to solve the problems of heavy storage burden and high overhead of an existing method. The scheme comprises the following steps: initializing a system; the vehicle and the RSU register to the TA, and the TA stores the related public key and the anonymous identity in the public block chain; after the vehicle enters the range of the RSU, bidirectional authentication is passed, and anonymous identity data is stored in the block chain; after the authentication succeeds, the vehicle uploads a message needing to be broadcasted to the IPFS, obtains an index, and sends the encrypted index to the RSU; and after the RSU acquires and verifies the message from the IPFS, the RSU broadcasts and stores the message in the block chain. According to the method, the public block chain and the IPFS are combined, the data and user privacy and tampering prevention are guaranteed, meanwhile, the block chain storage pressure and the system calculation and communication overhead are remarkably reduced, and safe and low-delay batch authentication is achieved.

Description

Technical Field

[0001] This invention belongs to the field of information security technology, and relates to blockchain technology, certificateless encryption algorithms and Interplanetary System Files (IPFS) in the field of information security. Background Technology

[0002] As a typical application of Internet of Things (IoT) technology in Intelligent Transportation Systems (ITS), Vehicular Ad Hoc Networks (VANETs) utilize onboard units (OBUs), roadside units (RSUs), and Dedicated Short Range Communication (DSRC) technologies to construct a dynamic, self-organizing vehicle-road cooperative communication platform. VANETs support real-time, reliable information exchange and collaborative computing between vehicles and infrastructure, playing a crucial role in enhancing road safety, optimizing traffic resource allocation, and improving traffic management efficiency.

[0003] Qi Xie et al.'s paper, *Provably Secure and Anonymous V2I and V2V Authentication Protocol for VANETs*, proposes a lightweight, anonymous V2I and V2V bidirectional authentication protocol based on Elliptic Curve Cryptography (ECC) for secure communication in vehicular ad hoc networks (VANETs). This method integrates Physically Unclonable Functions (PUFs) and biometric key technology, employing a dynamic pseudonym mechanism and a batch authentication strategy. However, this method increases implementation complexity and requires more system resources. Furthermore, its communication and computational overhead remains high in high-density vehicular environments.

[0004] In their paper, "Design of Blockchain-Based Lightweight V2I Handover Authentication Protocol for VANET," Seunghwan Son et al. proposed a lightweight V2I handover authentication protocol based on a consortium blockchain, addressing the secure and efficient authentication needs of vehicles moving between different Roadside Units (RSUs) in VANETs. This scheme integrates Elliptic Curve Cryptography (ECC) with consortium blockchain technology and employs the Algorand consensus mechanism to achieve decentralized handover information sharing and a lightweight authentication process. However, as blockchain nodes, RSUs need to store the complete ledger and participate in consensus, potentially increasing their storage and computational burden. Furthermore, there is still room for improvement in terms of communication and computational overhead.

[0005] Lu Wei et al. proposed a decentralized authentication key agreement scheme based on smart contracts and public blockchains in their paper "A Decentralized Authenticated Key Agreement Scheme Based on Smart Contract for Securing Vehicular Ad-Hoc Networks," addressing the secure communication needs of vehicular ad hoc networks (VANETs). This scheme implements vehicle access management and public key registration through smart contracts, optimizes on-chain storage using Bloom filters, and leverages elliptic curve cryptography and zero-knowledge proofs to achieve privacy-preserving key negotiation, completely eliminating reliance on trusted institutions (TAs).

[0006] However, transactions such as vehicle registration and public key uploads are still affected by blockchain confirmation delays, which may introduce latency in highly dynamic VANET environments. While the methods mentioned above improve the confidentiality and security of the authentication process to some extent, most of the proposed methods have some issues with storage and security, or some have high computational and communication costs. Therefore, for V2R authentication in vehicular ad hoc networks, a secure and efficient multi-vehicle authentication method combining public blockchain and IPFS is proposed. In vehicular ad hoc networks, this method can operate without certificate-based signatures. It not only improves signature computation efficiency while providing resistance to malicious KGC and RSU, but also stores authentication request data on the blockchain. Simultaneously, it utilizes IPFS to archive the interactive information generated during the notification phase, thereby alleviating the storage pressure on the blockchain within the VANET. This method safeguards the privacy and security of registered users in vehicular ad hoc networks from multiple aspects, including data privacy, user privacy data protection, and signature data tamper-proofing. Summary of the Invention

[0007] The purpose of this invention is to propose a highly secure and efficient multi-vehicle certificateless signature authentication method that combines blockchain and IPFS technologies. To protect the privacy and security of registered users in the vehicle terminal, this method stores the request data generated during the authentication process on the blockchain, while storing the interaction information generated during the notification phase on IPFS. This method leverages the storage advantages of blockchain while alleviating its storage pressure. It also reduces the computational overhead of communication and batch signing, improving the efficiency and security of in-vehicle information interaction.

[0008] This invention discloses a low-latency, blockchain-based in-vehicle self-organizing network security batch authentication method, comprising an authoritative institution, vehicle users, a public blockchain, roadside units, and IPFS. The authoritative institution will register the user's identity, ID... Vi Anonymous identity FID i Public key and public key and identity ID of roadside unitRSUj The authentication data is stored in a public blockchain for authorized nodes to access quickly and easily. The roadside unit first generates the necessary authentication message and corresponding signature and sends it to the target vehicle. The target vehicle then verifies the message and sends the message tuple and signature to the nearest target roadside unit, anonymously storing the generated authentication data on the public blockchain. Finally, the roadside unit verifies the vehicle's signature. After successful authentication between the roadside unit and the vehicle, the vehicle can store the message tuple to be broadcast in IPFS, obtain the corresponding index value, encrypt it again, and send it to the roadside unit. The roadside unit decrypts the ciphertext to obtain the index value and uses it to retrieve the corresponding stored data on IPFS for verification.

[0009] Specifically, the present invention is achieved through the following technical solutions.

[0010] The present invention discloses a secure and low-latency batch authentication method for blockchain-based in-vehicle self-organizing networks, comprising the following steps:

[0011] S1: TA generates a set of common params={P,F} based on the input security parameter λ. P H 1-7 (.)} and publish it on the public blockchain, while randomly generating its own private and public keys to provide the necessary data for two-way authentication between vehicles and roadside units. P is the point where the elliptic curve is generated, F p H represents a finite field. 1-7 (.) are all hashes (SHA-256). TA is a private, randomly selected secret value SK. TA Used as the master private key. Calculate the master public key: PK TA =SK TA *p;

[0012] S2: Vehicle V i (PK) Vi ID Vi ) is sent to TA via a secure channel, where ID Vi For vehicle V i The true identity, PK Vi For vehicle V i The public key. TA receives (PK) Vi ID Vi After that, first check the vehicle's identity, ID. Vi Whether it is reliable, if it passes the check, TA will calculate (FID) i A i B i PK TA , r i Send to registered vehicle V through a secure channel i Vehicle V iReceived TA's (FID) i A i, B i PK TA ,r i Then it was verified. Finally, vehicle V i (A) i B i C i D i E i PK Vi FID i , Rep(.),δ i Private storage, where Rep(.) is the reproduction function of the fuzzy extractor;

[0013] S3: TA is RSU j Select random number z j SK RSUj SK RSUj As its private key, set RSU j Identity ID is ID RSUj TA will calculate the data tuple (ID) RSUj , x j , z j SK RSUj PK RSUj PK TA ,K RSUj Send to RSU j RSU j Receive (ID) RSUj , x j , z j SK RSUj PK RSUj PK TA , K RSUj Then, it is verified. If the condition is not met, the tuple is rejected and reported to the TA. Otherwise, RSU is processed. j Randomly generate a challenge Cha j The tuple (ID) is then calculated. RSUj , F j , Gj, Z j Cha j PK RSUj , z j ) and store it;

[0014] S4: When vehicle V i Entering the roadside unit RSU j Within the scope, first RSU j Generate verification message M j=(ID RSUj , T1,T a ), T a Use the current timestamp. Calculate its verification message signature б. Mj RSU j (M) j , б Mj )Sent to vehicle V through a secure channel i Vehicle V i Receive (M) j , б Mj After that, first verify the timeliness of the tuple, vehicle V i tuple (M) Vi-RSUj ,б Vi-RSUj Transmitted to the corresponding RSU via a secure channel j In addition, vehicle V i tuple (PID) Vi-RSUj T2) is stored in the blockchain. Finally, RSU j Verify message tuple (M) Vi-RSUj ,б Vi-RSUj The accuracy of ) is as follows. If it passes, then vehicle V i with RSU j Once mutual authentication is successful, communication can begin.

[0015] S5: When vehicle V i The message that needs to be broadcast is m i Vehicle V i First, let the tuple {AC} Vi PID Vi-RSUj Q i T3} is sent to the RSU via a secure channel. j RSU j Received tuple {AC Vi PID Vi-RSUj Q i After T3}, the roadside unit obtains the ciphertext by decrypting it. RSU j from Extract the corresponding identity from IPFS Obtain the vehicle's uploaded PID from IPFS. Vi-RSUj ID Vi , m i Q i Finally, the anonymous identity PID was used. Vi-RSUj and ID Vi A one-to-one correspondence was established. Finally, the RSU... j Message m i Broadcast and store on the blockchain.

[0016] Furthermore, step S2 specifically includes the following steps:

[0017] S2.1: Vehicle V i Generate random number SK Vi As the private key, calculate the vehicle's public key PK. Vi =SK Vi *p, will (PK) Vi ID Vi ) is sent to TA via a secure channel, where ID Vi For vehicle V i The true identity of the person in question;

[0018] S2.2: TA Receive (PK) Vi ID Vi After that, first check the vehicle identification ID. Vi Whether it is reliable or not, if it passes the check, then TA selects a random number r. i a i ;

[0019] S2.3: Calculate vehicle V i Anonymous identity FID Vi =H2(ID Vi ||T Vi H1(PK) Vi ⊕PK TA )‖r i ), where T Vi Calculate A using the current timestamp. i =a i *p, B i =H2(ID Vi FID Vi ‖PK Vi ||A i )*SK TA +a i ;

[0020] S2.4: TA will (FID) Vi A i B i PK TA , r i Send to registered vehicle V through a secure channel i ;

[0021] S2.5: Vehicle V i Received TA's (FID) Vi A i B i PK TA , r i Then first Bi Verify and test B i =H2(ID Vi FID Vi ‖PK Vi ||A i )PK TA +A i Does the equation hold true? If it does, then calculate (PW). Vi ,δ i = Gen(Bio) Vi ), where Gen(.) is the generator function of the fuzzy extractor, Bio Vi For vehicle V i The user's biometric information is used as the output of the generator function, which is the corresponding parameter δ. i and bio-key PW Vi C i =B i ⊕H PWi Where H PWi =H4(ID Vi PW Vi );C i =SK Vi ⊕H5(r i ); E i = H4(FID Vi SK Vi );

[0022] S2.6: Vehicle V i (A) i B i C i D i E i PW Vi , Rep(.),δ i Private storage, where Rep(.) is the reproduction function of the fuzzy extractor.

[0023] Furthermore, step S3 specifically includes the following steps:

[0024] S3.1: TA is RSU j Select random number z j SK RSUj SK RSUj As its private key, set RSU j Identity ID is ID RSUj ;

[0025] S3.2: TA calculates PK RSUj =SK RSUj *p, K RSUj =H4 (IDRSUj SK TA Z j =z j *p where PK RSUj For RSU j public key, K RSUj For shared keys;

[0026] S3.3: TA calculates x j =H3(ID RSUj ‖PK RSUj ‖PK TA ) *SK TA +z j TA will (ID) RSUj , x j , z j SK RSUj PK RSUj PK TA , K RSUj Send to RSU j ;

[0027] S3.4: RSU j Receive (ID) RSUj , x j , z j SK RSUj PK RSUj PK TA , K RSUj After that, first verify the equation x. j *p=H3(ID RSUj ‖PK RSUj ‖PK TA If the condition is not met, reject the tuple and report it to TA.

[0028] S3.5: Otherwise RSU j Randomly generate a challenge Cha j And calculate Res j =PUF(Cha j ), where PUF(.) is the physically unclonable function, and Res j As a physically non-clonable function, F j = K RSUj ⊕H5(Res j ), G j = (x j SK RSUj )⊕H4(Res j ‖F j RSU j Storage (ID) RSUj , Fj G j Z j Cha j PK RSUj , z j ).

[0029] Furthermore, step S4 specifically includes the following steps:

[0030] When vehicle V i Entering the roadside unit RSU j Within the range;

[0031] S4.1: Vehicle V i Enter Bio Vi And calculate PW' Vi =Rep(Bio' Vi ,δ' i ), and thus verify the equation: H PWi =H4(ID Vi PW' Vi If the condition is not met, then V is true. i with RSU j Cancel certification, vehicle V i Exit the authentication process and report this incident to TA. Otherwise, vehicle V i Continue verifying the equation: B i =C i ⊕H PWi SK Vi =D i ⊕H5(r i If the condition is not met, then V is true. i with RSU j Cancel certification, vehicle V i Exit the authentication process and report this event to the TA; otherwise, proceed to S4.2.

[0032] S4.2: By RSU j Select a random number t1∈Z * q And calculate T1=t1*p, RSU j Let the verification message M be... j =(T a , T1,ID RSUj ), T a This is the current timestamp. RSU j Calculate the signature of the verification message:

[0033] б Mj = t1+H(T a , T1)*(SK RSUj + B i (1)

[0034] RSU j (б) Mj M j ) Sent to vehicle V through a secure channel i ;

[0035] S4.3: Vehicle V i Receive (б) Mj M j After that, first verify the timeliness of the tuple. If the delay is greater than the specified time delay Δt, then the vehicle V i Authentication will be denied, and the incident will be reported to TA. Otherwise, vehicle V i Retrieve the public key of the corresponding roadside unit and the system master public key stored in the blockchain and verify the equation:

[0036] б Mj *p =T+(PK RSUj +H2(ID Vi FID Vi ‖PK TA ||A i )PK TA +A i H7(T1,T) a (2)

[0037] If the authentication fails, the process ends; otherwise, proceed to step four.

[0038] S4.4: Vehicle V i Call the ID of the corresponding roadside unit stored in the blockchain RSUj And select random numbers d,t1∈Z * q Calculate T2 = t * p, PID 1 Vi-RSUj =d*p, PID 2 Vi-RSUj = ID RSUj ⊕H5(d*PK RSUj Vehicle V i with RSU j Anonymity in communication is:

[0039] PID Vi-RSUj =(PID 1 Vi-RSUj PID 2 Vi-RSUj (3)

[0040] Vehicle V i Let M Vi-RSUj =(T2, T b PID Vi-RSUj ), where Tb Calculate using the current timestamp:

[0041] б Vi-RSUj =t2+SK Vi *H3(T2‖T b ‖PID Vi-RSUj (4)

[0042] Vehicle V i tuple (б) Vi-RSUj M Vi-RSUj Transmitted to the corresponding RSU via a secure channel j In addition, vehicle V i tuple (PID) Vi-RSUj (T2) Stored in the blockchain;

[0043] S4.5: RSU j First, verify the timeliness of the tuple. If the delay is greater than the specified time delay Δt, then RSU j Deny authentication and report the incident to the TA. Otherwise, proceed with RSU. j Calculate Res j =PUF(Cha j ), K RSUj =F i ⊕H(Res j ), (x j SK RSUj )=G i ⊕H4(Res j ‖F i ), then RSU j Verify Equation ID RSUj = PID 2 Vi-RSUj ⊕H5(d*PK RSUj Final verification of б Vi-RSUj *P=T2+PK Vi *H3(T2‖T b ‖PID Vi-RSUj If it passes, then vehicle V i with RSU j Once mutual authentication is successful, communication can begin.

[0044] Furthermore, step S5 specifically includes the following steps:

[0045] Let vehicle V i The message that needs to be broadcast is m i ;

[0046] S5.1: Vehicle V i Calculate Q i =H2(PID Vi-RSUj‖T3‖H5(m i ) ‖ID RSUj ), where T3 is the current timestamp.

[0047] and {PID Vi-RSUj ID Vi , m i Q i Uploaded to the InterPlanetary File System (IPFS), and the corresponding IP address obtained from IPFS. IDi I IDi Used to index vehicle V from IPFS i The corresponding {PID Vi-RSUj ID Vi , m i Q i Vehicle V i Let m Vi ={PID Vi-RSUj ID Vi , I Idi The ciphertext, AC, is obtained using an encryption algorithm. Vi =Enc(PK RSUj , m Vi ), then vehicle V i Let the tuple { AC Vi PID Vi-RSUj Q i T3} is sent to the RSU via a secure channel. j ;

[0048] S5.2: RSU j Received tuple {AC Vi PID Vi-RSUj Q i After T3}, if the delay is greater than the specified time delay Δt, then RSU j Authentication denied, and the incident reported to the TA. RSU j Calculate Dec(SK) RSUj AC Vi ) to obtain m Vi ;

[0049] S5.3: Subsequently RSU j From m Vi Extract the corresponding identity I from IPFS IDi Obtain the vehicle's uploaded PID from IPFS Vi-RSUj ID Vi , m i Q i Finally, the anonymous identity PID was used. Vi-RSUj and ID ViPerform a one-to-one matching; if the matching is successful, RSU... j Verify equation Q i =H2(PID Vi-RSUj ‖T3‖H5(m i ) ‖ID RSUj If the condition is true, then RSU... j Message m i Broadcast and store on the blockchain.

[0050] This invention proposes a secure and efficient batch authentication scheme that integrates public blockchain and IPFS for the V2R authentication process in vehicular ad hoc networks. This invention can be executed without certificate-based signatures, improving signature computation efficiency while resisting malicious KGC and RSU attacks. It also utilizes IPFS to archive interactive information generated during the notification phase, thereby alleviating the storage pressure on the public blockchain in VANETs. This invention safeguards the privacy and security of registered users in vehicular ad hoc networks from multiple aspects, including data privacy, user privacy data protection, and signature data tamper-proofing. Furthermore, through security analysis, based on Theorems 1 and 2, the identity and message authentication of this invention are unforgeable. Compared with other methods, this invention improves both communication efficiency and performance. Attached Figure Description

[0051] Figure 1 This is a system model diagram of the identity authentication method combining blockchain and interplanetary system files according to the present invention.

[0052] Figure 2 This is a data interaction diagram for the registration phase of the identity authentication method combining blockchain and StarCraft system files, as presented in this invention.

[0053] Figure 3 This is a data interaction diagram of the authentication phase of the identity authentication method combining blockchain and StarCraft system files according to the present invention.

[0054] Figure 4 This is a data interaction diagram of the notification phase of the identity authentication method combining blockchain and interplanetary system files in this invention.

[0055] Figure 5 This is a comparison chart showing the computational overhead of the authentication method combining blockchain and interplanetary system files in this invention.

[0056] Figure 6 This is a comparison chart showing the computational overhead of batch authentication for the identity authentication method combining blockchain and Interplanetary System files in this invention.

[0057] Figure 7 This is a comparison chart of the communication overhead of the identity authentication methods based on blockchain and Interplanetary System files in this invention. Detailed Implementation

[0058] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0059] 1. The model structure layout of the present invention.

[0060] like Figure 1 The specific parameters for the overall structure of this invention are defined as follows:

[0061] Vehicles: Each intelligent vehicle is equipped with a wireless-enabled OBU. The OBU obtains vehicle dynamic information from the RSU or other vehicles and shares traffic-related messages via DSRC technology or the PC5 interface between V2V and V2I communication. To avoid privacy breaches, each vehicle communicates using an anonymous identity issued by the KGC. Furthermore, each OBU is synchronized with the system time of all entities in the VANETs.

[0062] The system model consists of five entities: Trusted Authority (TA), public blockchain, RSU and InterPlanetary File System (IPFS), and vehicle, such as Figure 1 As shown, the definition of each entity is as follows:

[0063] Trusted Authority (TA): As the authoritative entity responsible for vehicle authentication, key management, and security policy formulation, the TA ensures the authenticity, integrity, and non-repudiation of communications by issuing trusted certificates and monitoring network behavior. It is responsible for system initialization and generating a series of public parameters to help roadside units and users complete registration.

[0064] Roadside Units (RSUs): Roadside unit nodes provide communication and interaction between vehicles and infrastructure. They communicate bidirectionally with vehicles through wireless communication technologies such as in-vehicle communication, Wi-Fi, and cellular networks. Specifically, RSUs collect data from roadside vehicle sensors, traffic lights, cameras, and other devices, and transmit this data to the cloud or other central locations for use by traffic management and intelligent transportation systems. Simultaneously, their location beside the road increases the coverage of vehicle communication, improving communication reliability and continuity to facilitate user authentication, task data processing, and consensus. They possess powerful computing and storage capabilities, and as management nodes in the blockchain, they can view vehicle messages in real time and record them in the blockchain.

[0065] InterPlanetary File System (IPFS): IPFS is a content-addressable distributed storage protocol that uses a distributed network to achieve efficient and reliable data sharing and persistent storage between vehicle nodes, supporting fast content retrieval in dynamic topologies and data transmission under single point of failure.

[0066] Public blockchains have low barriers to entry, allowing the system to read data and send transaction confirmations by default. They incentivize and promote competitive ledger recording through tokens, protecting user rights from the influence of application developers. As a decentralized distributed ledger technology, it stores data in blocks and uses cryptographic methods to ensure data security and immutability. This invention utilizes these characteristics to encrypt and store user privacy information in the blockchain to ensure the validity and integrity of user identities, while also storing transaction information in the blockchain to ensure the fairness of transactions. This method uses a public blockchain to store road and traffic information, allowing registered, trusted users to promptly obtain the traffic information they need from the public blockchain stored on the OBU.

[0067] 2. The identity authentication method based on blockchain and interplanetary system files of the present invention

[0068] The present invention proposes a secure and efficient authentication and encryption method combining blockchain and IPFS in VANETs communication. The node registration process is as follows: Figure 2 As shown.

[0069] Vehicle registration: Vehicle V i The user submits their identity information and public key to the TA, who then performs a series of calculations to obtain the (FID). i A i, B i PK TA , r i Then send it to vehicle V i Then vehicle V i After verifying the data, the data required for subsequent authentication (A) is calculated. i B i C i D i E i PK Vi FID i , Rep(.), δ i RSU registration: TA obtains the data tuple (ID) after calculation. RSUj , x j , z j SK RSUj PK RSUj PK TA , K RSUj ) and send it to the RSU. After verifying receipt, the RSU calculates the data tuple (ID) required for authentication. RSUj , F j , Gj, Z j Cha j PK RSUj , zj ).

[0070] In VANETs communication, a secure and efficient authentication and encryption method combining blockchain and IPFS is used, such as the authentication process... Figure 3 As shown.

[0071] When vehicle V i Entering the roadside unit RSU j Within the scope, first RSU j Generate verification message M j =(ID RSUj , T1, T a ), T a Use the current timestamp. Calculate its verification message signature б. Mj RSU j (M) j , б Mj )Sent to vehicle V through a secure channel i Vehicle V i Receive (M) j , б Mj After that, first verify the timeliness of the tuple, vehicle V i tuple (б) Vi-RSUj M Vi-RSUj Transmitted to the corresponding RSU via a secure channel j In addition, vehicle V i tuple (PID) Vi-RSUj T2) is stored in the blockchain. Finally, RSU j Verification message tuple (б) Vi-RSUj M Vi-RSUj The accuracy of ) is as follows. If it passes, then vehicle V i with RSU j Once mutual authentication is successful, communication can begin.

[0072] In VANETs communication, a secure and efficient authentication and encryption method combining blockchain and IPFS is used for the notification process, as follows: Figure 4 As shown.

[0073] When vehicle V i The message that needs to be broadcast is m i Vehicle V i First, let the tuple {AC} Vi PID Vi-RSUj Q i T3} is sent to the RSU via a secure channel. j RSU j Received tuple {AC Vi PID Vi-RSUj Q iAfter T3}, the roadside unit obtains m by decrypting the ciphertext. Vi RSU j From m Vi Extract the corresponding identity I from IPFS IDi Obtain the vehicle's uploaded PID from IPFS. Vi-RSUj ID Vi , m i Q i Finally, the anonymous identity PID was used. Vi-RSUj and ID Vi A one-to-one correspondence was established. Finally, the RSU... j Message m i Broadcast and store on the blockchain.

[0074] 3. Security Guarantee of the Invention

[0075] (1) Privacy: All vehicles must submit their real IDs to the Telecommunications Authority before joining VANETs. To protect vehicle privacy, a trusted authority generates a pseudonymous PID based on the vehicle's ID, ensuring that no third party other than the trusted authority can obtain the vehicle's real ID. During the authentication process, each RSU uses anonymous information to authenticate the vehicle user without compromising the vehicle user's privacy.

[0076] (2) Non-repudiation: All information data transmitted by the vehicle will be recorded on a public blockchain. This blockchain can be used to trace the transmitted data back to the actual vehicle that sent it. Therefore, anonymous information data sent by the vehicle can be verified, and the vehicle user cannot deny the messages they sent.

[0077] (3) Immutable Messages: Vehicle message data is encrypted using a key before uploading, and the resulting ciphertext is transmitted to IPFS. Due to the inherent properties of IPFS, the encrypted message data remains unchanged. Any form of data tampering will result in content alteration.

[0078] (4) Message Integrity Verification: In the provable security section, we have demonstrated that it is impossible for an attacker to successfully forge a valid signature. If data is maliciously tampered with during transmission, we can detect it through verification.

[0079] (5) Replay attack resistance: When the message sender executes the signature algorithm, in order to ensure that the message is fresh enough, the current timestamp T of the signature is used. i The message is included in the signed message. If the recipient receives the email after Δt (the time Δt was sent), the recipient can reject the email. Therefore, our authentication method is resistant to replay attacks.

[0080] 4. Communication Overhead Analysis of the Invention

[0081] The output lengths of Hash (SHA-256), an ECC point, and a random number are 256 bits, 160 bits, and 256 bits, respectively. With this data, the communication overhead of the comparative literature can be obtained. Table 1 shows a comparison of the communication overhead of Qi Xie et al.'s "Provably Secure and Anonymous V2I and V2V Authentication Protocol for VANETs," Seunghwan Son et al.'s "Design of Blockchain-Based Lightweight V2I Handover Authentication Protocol for VANETs," Lu Wei et al.'s "A Decentralized Authenticated KeyAgreement Scheme Based on Smart Contract for Securing Vehicular Ad-Hoc Networks," and Zixuan Ding et al.'s "Provable secure and lightweight blockchain-based V2I handover authentication and V2V broadcast protocol for VANETs."

[0082] Table 1. Comparison of Communication Overhead for Each Method

[0083]

[0084] 5. Computational Overhead Analysis of the Invention

[0085] The computational overhead of the signature / decryption process in this invention was evaluated on a Raspberry Pi 4B equipped with a quad-core ARM Cortex-A72 processor, considering both computational and communication overhead. Regarding computational overhead, a computer was used to obtain the runtime of the cryptographic operations required by the program. Let T... H T Sig T ECC The time spent on hash (SHA256) operations, signature based on asymmetric encryption (DSA1024), and elliptic curve multiplication operations is recorded in Table 2. Based on the calculation results, the execution time of the above-mentioned cryptography is recorded in Table 2. Tables 3 and 4 show a comparison of the authentication process and batch authentication computation overhead between this method and the existing methods mentioned above.

[0086] Table 2. Running time of various password operations

[0087]

[0088] Table 3 Comparison of the single authentication overhead of each method with that of the present invention

[0089]

[0090] Table 4 Comparison of batch authentication overhead between various methods and the present invention

[0091]

[0092] Figure 5 This chart compares the computational overhead of the authentication process performed by this invention with that of other methods. For a single authentication operation, the vehicle-mounted terminal of this invention requires 3 elliptic curve multiplication operations and 5 hash operations, resulting in a computational overhead of 3T. H +5T ECC =13.107 milliseconds, while the RSU terminal requires 5 scalar multiplication operations and 4 hash operations, i.e., the computational overhead is 5T. H +4T ECC =10.535 milliseconds, total overhead is 8T H +9T ECC =23.642 milliseconds.

[0093] Figure 6 A comparison chart of the computational overhead of this invention and other methods in performing batch authentication shows that, for n authentications, this invention requires a vehicle-side computational overhead of 3nT. H +5nT ECC Milliseconds, RSU computation overhead is 5nT H +(2n+2)T ECC Milliseconds, total overhead is 8nT H +(7n+2)T ECC Milliseconds. This demonstrates the significant advantage of this invention in VANETs environments with massive data volumes.

Claims

1. A secure and low-latency batch authentication method for blockchain-based in-vehicle self-organizing networks, characterized in that, Includes the following steps: S1: TA generates a set of common params={P,F} based on the input security parameter λ. P H 1-7 (.)} and publish it on the public blockchain, while randomly generating its own private and public keys to provide the necessary data for two-way authentication between vehicles and roadside units; P is the point where the elliptic curve is generated, F p H represents a finite field. 1-7 (.) are all hashes (SHA-256); TA is a private, randomly selected secret value SK. TA As the master private key; calculate the master public key: PK TA =SK TA *p; S2: Vehicle V i (PK) Vi ID Vi ) is sent to TA via a secure channel, where ID Vi For vehicle V i The true identity, PK Vi For vehicle V i The public key; TA Receive (PK) Vi ID Vi After that, first check the vehicle's identity, ID. Vi Whether it is reliable, if it passes the check, TA will calculate (FID) i A i, B i PK TA , r i Send to registered vehicle V through a secure channel i Vehicle V i Received TA's (FID) i A i B i PK TA , r i Then verify it; finally, vehicle V i (A) i B i C i D i E i PK Vi FID i , Rep(.),δ i Private storage, where Rep(.) is the reproduction function of the fuzzy extractor; S3: TA is RSU j Select random number z j SK RSUj SK RSUj As its private key, set RSU j Identity ID is ID RSUj TA will calculate the data tuple (ID) RSUj , x j ,z j SK RSUj PK RSUj PK TA , K RSUj Send to RSU j RSU j Receive (ID) RSUj , x j , z j SK RSUj PK RSUj PK TA , K RSUj Then, verify the tuple. If it is not true, reject the tuple and report it to TA; otherwise, RSU. j Randomly generate a challenge Cha j The tuple (ID) is then calculated. RSUj , F j , Gj, Z j Cha j PK RSUj ,z j ) and store it; S4: When vehicle V i Entering the roadside unit RSU j Within the scope, first RSU j Generate verification message M j =(ID RSUj , T1, T a ), T a Use the current timestamp; and calculate its verification message signature б. Mj RSU j (M) j , б Mj )Sent to vehicle V through a secure channel i Vehicle V i Receive (M) j , б Mj After that, first verify the timeliness of the tuple, vehicle V i tuple (M) Vi-RSUj ,б Vi-RSUj Transmitted to the corresponding RSU via a secure channel j In addition, vehicle V i tuple (PID) Vi-RSUj T2) is stored in the blockchain; finally, RSU j Verify message tuple (M) Vi-RSUj ,б Vi-RSUj The accuracy of ); if passed, then vehicle V i with RSU j Once mutual authentication is successful, communication can begin. S5: When vehicle V i The message that needs to be broadcast is m i Vehicle V i First, let the tuple {AC} Vi PID Vi-RSUj Q i T3} is sent to the RSU via a secure channel. j RSU j Received tuple {AC Vi PID Vi-RSUj Q i After T3}, the roadside unit obtains the ciphertext by decrypting it. ; RSU j from Extract the corresponding identity from IPFS Obtain the vehicle's uploaded PID from IPFS. Vi-RSUj ID Vi , m i Q i Finally, the anonymous identity PID was used. Vi-RSUj and ID Vi Perform one-to-one correspondence; finally, RSU j Message m i Broadcast and store on the blockchain.

2. The blockchain-based vehicle self-organizing network security and low-latency batch authentication method according to claim 1, characterized in that, Step S2 includes the following steps: S2.1: Vehicle V i Generate random number SK Vi As the private key, calculate the vehicle's public key PK. Vi =SK Vi *p, will (PK) Vi ID V ) is sent to TA via a secure channel, where ID Vi For vehicle V i The true identity of the person in question; S2.2: TA Receive (PK) Vi ID Vi After that, first check the vehicle identification ID. Vi Whether it is reliable or not, if it passes the check, then TA selects a random number r. i a i ; S2.3: Calculate vehicle V i Anonymous identity FID Vi =H2(ID Vi ||T Vi H1(PK) Vi ⊕PK TA )‖r i ), where T Vi Calculate A using the current timestamp. i =a i *p, B i =H2(ID Vi FID Vi ‖PK Vi ||A i )*SK TA +a i ; S2.4: TA will (FID) Vi A i B i PK TA , r i Send to registered vehicle V through a secure channel i ; S2.5: Vehicle V i Received TA's (FID) Vi A i B i PK TA , r i Then first B i Verify and test B i =H2(ID Vi FID Vi ‖PK Vi ||A i )*PK TA + A i Does the equation hold true? If it does, then calculate (PW). Vi ,δ i = Gen(Bio) Vi ), where Gen(.) is the generation function of the fuzzy extractor, Bio Vi For vehicle V i The user's biometric information is used as the output of the generator function, which is the corresponding parameter δ. i and bio-key PW Vi C i =B i ⊕H PWi Where H PWi =H4(ID Vi PW Vi );C i =SK Vi ⊕H5(r i ); E i =H4(FID Vi SK Vi ); S2.6: Vehicle V i (A) i B i C i D i E i PW Vi , Rep(.),δ i Private storage, where Rep(.) is the reproduction function of the fuzzy extractor.

3. The blockchain-based vehicle self-organizing network security and low-latency batch authentication method according to claim 1, characterized in that, Step S3 includes the following steps: S3.1: TA is RSU j Select random number z j SK RSUj SK RSUj As its private key, set RSU j Identity ID is ID RSUj ; S3.2: TA calculates PK RSUj =SK RSUj *p, K RSUj =H4(ID RSUj SK TA Z j =z j *p where PK RSUj For RSU j public key, K RSUj For shared keys; S3.3: TA calculates x j =H3(ID RSUj ‖PK RSUj ‖PK TA )*SK TA +z j TA will (ID) RSUj , x j , z j SK RSUj PK RSUj PK TA , K RSUj Send to RSU j ; S3.4: RSU j Receive (ID) RSUj , x j , z j SK RSUj PK RSUj PK TA , K RSUj After that, first verify the equation x. j *p=H3(ID RSUj ‖PK RSUj ‖PK TA If the condition is not met, reject the tuple and report it to TA. S3.5: Otherwise RSU j Randomly generate a challenge Cha j And calculate Res j =PUF(Cha j ), where PUF(.) is the physically unclonable function, and Res j As a physically non-clonable function, F j = K RSUj ⊕H5(Res j ), G j = (x j SK RSUj )⊕H4(Res j ‖F j RSU j Storage (ID) RSUj , F j G j Z j Cha j PK RSUj ,z j ).

4. The blockchain-based vehicle self-organizing network security and low-latency batch authentication method according to claim 1, characterized in that, Step S4 includes the following steps: When vehicle V i Entering the roadside unit RSU j Within the range; S4.1: Vehicle V i Enter Bio Vi And calculate PW' Vi =Rep(Bio' Vi , δ' i ), and thus verify the equation: H PWi =H4(ID Vi PW' Vi If the condition is not met, then V is true. i with RSU j Cancel certification, vehicle V i Exit the authentication process and report this incident to TA; otherwise, vehicle V i Continue verifying the equation: B i =C i ⊕H PWi SK Vi =D i ⊕H5(r i If the condition is not met, then V is true. i with RSU j Cancel certification, vehicle V i Exit the authentication process and report this event to the TA; otherwise, proceed to S4.

2. S4.2: By RSU j Select a random number t1∈Z * q And calculate T1=t1*p, RSU j Let the verification message M be... j =(T a , T1, ID RSUj ), T a This is the current timestamp; RSU j Calculate the signature of the verification message: б Mj = t1+H7(T a , T1)*(SK RSUj +B i )(1) RSU j (б) Mj M j ) Sent to vehicle V through a secure channel i ; S4.3: Vehicle V i Receive (б) Mj M j After that, first verify the timeliness of the tuple. If the delay is greater than the specified time delay Δt, then the vehicle V i Authentication will be refused, and the incident will be reported to TA; otherwise, vehicle V i Call the public key of the corresponding roadside unit and the system master public key stored in the blockchain and verify the equation: б Mj *p =T1+(PK RSUj +H4(ID Vi ‖FID Vi ‖PK TA ‖A i )PK TA +A i )H7(T1,T a )(2) If the authentication fails, the process ends; otherwise, proceed to step four. S4.4: Vehicle V i Call the ID of the corresponding roadside unit stored in the blockchain RSUj And select random numbers d,t1∈Z * q Calculate T2 = t * p, PID 1 Vi-RSUj =d*p, PID 2 Vi-RSUj = ID RSUj ⊕H5(d*PK RSUj Vehicle V i with RSU j Anonymity in communication is: PID Vi-RSUj =(PID 1 Vi-RSUj , PID 2 Vi-RSUj )(3) Vehicle V i Let M Vi-RSUj =(T2, T b PID Vi-RSUj ), where T b Calculate using the current timestamp: b Vi-RSUj =t2+SK Vi *H3(T2-T b ‖PID Vi-RSUj (4) Vehicle V i tuple (б) Vi-RSUj M Vi-RSUj Transmitted to the corresponding RSU via a secure channel j In addition, vehicle V i tuple (PID) Vi-RSUj (T2) Stored in the blockchain; S4.5: RSU j First, verify the timeliness of the tuple. If the delay is greater than the specified time delay Δt, then RSU j Refuse authentication and report the incident to the TA; otherwise, RSU. j Calculate Res j =PUF(Cha j ), K RSUj =F i ⊕H(Res j ), (x j SK RSUj )=G i ⊕H4(Res j ‖F i ), then RSU j Verify Equation ID RSUj = PID 2 Vi-RSUj ⊕H5(d*PK RSUj Final verification of б Vi-RSUj *P=T2+PK Vi *H3(T2‖T b ‖PID Vi-RSUj If it passes, then vehicle V i with RSU j Once mutual authentication is successful, communication can begin.

5. The blockchain-based vehicle self-organizing network security and low-latency batch authentication method according to claim 1, characterized in that, Step S5 includes the following steps: Let vehicle V i The message that needs to be broadcast is m i ; S5.1: Vehicle V i Calculate Q i =H2(PID Vi-RSUj ‖T3‖H5(m i ) ‖ID RSUj ), where T3 is the current timestamp; and {PID Vi-RSUj ID Vi , m i Q i Uploaded to the InterPlanetary File System (IPFS), and the corresponding IP address obtained from IPFS. IDi I IDi Used to index vehicle V from IPFS i The corresponding {PID Vi-RSUj ID Vi ,m i Q i Vehicle V i Let m Vi ={PID Vi-RSUj ID Vi , I Idi The ciphertext, AC, is obtained using an encryption algorithm. Vi =Enc(PK RSUj , m Vi ), then vehicle V i Let the tuple { AC Vi PID Vi-RSUj Q i T3} is sent to the RSU via a secure channel. j ; S5.2: RSU j Received tuple {AC Vi ,PID Vi-RSUj Q i After T3}, if the delay is greater than the specified time delay Δt, then RSU j Refuse authentication and report the incident to the TA; RSU j Calculate Dec(SK) RSUj AC Vi ) to obtain m Vi ; S5.3: Subsequently RSU j From m Vi Extract the corresponding identity I from IPFS IDi Obtain the vehicle's uploaded PID from IPFS. Vi-RSUj ID Vi , m i Q i Finally, the anonymous identity PID was used. Vi-RSUj and ID Vi Perform a one-to-one matching; if the matching is successful, RSU... j Verify equation Q i =H2(PID Vi-RSUj ‖T3‖H5(m i )‖ID RSUj If the condition is true, then RSU... j Message m i Broadcast and store on the blockchain.

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