In vehicular ad hoc networks (VANETs), distributed identity authentication provides the foundation for securing sessions among entities over wireless channels while eliminating single points of failure. However, existing distributed authentica tion schemes for VANETs typically make unrealistic assumptions about node reliability and trustworthiness, failing to account for scenarios where authentication nodes may be compromised or collude with vehicles. Moreover, these schemes expose the com munication process to linkability attacks while allowing vehicles to self-register their public keys. To address these limitations, we propose a privacy-preserving and accountable distributed collab orative authentication scheme for VANETs that is resilient to ma licious nodes. Using threshold signature techniques, distributed authentication nodes collaboratively perform decentralized ve hicle identity authentication using a predefined threshold. Zero knowledge proof protects the privacy of the signing process while maintaining accountability and effectively preventing malicious behavior by nodes under external or internal adversarial attacks. Furthermore, vehicles self-register their public keys via smart contracts and blockchain technology, ensuring anonymity and unlinkability during registration while enabling the traceability of malicious vehicles. Security and performance analyses show that the proposed scheme enhances the security and robustness of distributed collaborative authentication in VANETs, achieving a better balance between computational and communication costs than existing schemes

In recent years, vehicle announcement sharing has become increasingly important in intelligent transportation networks. However, the demand for secure communication and real-time responses necessitates the development of an efficient and confidential announcement sharing scheme. Existing solutions are constrained by inadequate privacy in inter-group sharing and lack of storage security consideration. To address these issues, we propose a blockchain-assisted secure announcement sharing scheme with controllable verifiable distributed security. This scheme constructs a re-encrypted group signature framework to achieve controlled confidentiality of announcements while ensuring efficient and secure sharing. Additionally, by designing a lightweight verification algorithm powered by the Inter Planetary File System (IPFS) and blockchain, the scheme ensures rapid verifiable secure both the initial and long-term storage of announcements. Security proof and analysis show that the proposed scheme offers enhanced security and robust privacy protection. Performance analysis demonstrates that, while providing better computational efficiency than other schemes, the proposed scheme maintains low communication overhead and smaller storage verification costs, outperforming existing announcement sharing schemes.

In vehicular ad-hoc networks (VANETs), message reporting is an effective method for improving traffic safety and efficiency. Most existing VANET message reporting schemes rely on the trust value of a single vehicle to determine message authenticity, which leads to unreliable message sources. Even multi vehicle-assisted reporting schemes are limited by the assumption that all vehicles have the same credibility, which does not reflect the actual dynamic VANET environment in which vehicles have different credibilities. To address this issue, we propose a blockchain-assisted VANET message reporting scheme with weighted threshold signatures. Through the design of weights, the credibility of different vehicles is quantified, and the impact of vehicles on the signing process is differentiated. Threshold signature generation relies on the weight sum of all signatories reaching a predetermined threshold, to enable flexible and reliable message reporting. Security analysis shows that our proposed scheme combined with blockchain can satisfy the security and privacy requirements of VANET message reporting. Performance analysis indicates that our proposed scheme outperforms the most advanced VANET message reporting schemes in terms of transmission and computation performance.

With the rapid development of vehicular ad-hoc networks (VANETs) and the increasing diversification of user demands, interactions between different management domains have become more frequent. Identity authentication is an effective way to establish cross-domain trust and secure communication. However, the existing cross-domain authentication schemes of VANETs are limited to the same management or authentication technology for each domain and rely on centralized cross-domain identity management. Even distributed management solutions encounter latency sensitivity, security and privacy challenges. To address these challenges, we propose a blockchain-assisted revocable cross-domain authentication scheme for VANETs. The proposed scheme can establish trust between domain entities by deploying different authentication methods and using distributed management to avoid single-point failures. In addition, the scheme can revoke the identity of malicious vehicles by updating the group public key, thereby ensuring the security and privacy of cross-domain Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communication. This design avoids the additional impacts of blockchain technology constraints on the high mobility and real-time requirements of VANETs. Security analysis and performance evaluation show that our scheme can resist more attacks and has better security than other related schemes while also achieving a better balance between communication and computational cost.

In Vehicular Ad-hoc Networks (VANETs), vehicles must authenticate their identities before accessing services. However, existing authentication schemes based on anonymous credentials still face single-point failure in multi-authority scenarios. In addition, in traditional anonymous credential schemes, the public key of credential authority is used directly to verify the credential, which may increase the risk of vehicle privacy being misused. To address these issues, we propose a decentralized threshold credential management system with fine-grained authentication for VANETs. The decentralized credential management architecture is proposed for VANETs with multiple credential authorities, each credential authority consists of multiple credential managers who issue credentials using the threshold mechanism, effectively solving the single-point failure. Based on this architecture, we design a fine-grained, privacy-preserving authentication scheme that allows vehicles to autonomously perform selective attribute disclosure, credential aggregation, and randomization before requesting verification from the Cloud Service Provider, thereby achieving a balance between privacy preservation and authentication efficiency. The security proofs and analysis show that our scheme satisfies the target security properties. Performance evaluations indicate that our scheme enables efficient, flexible credential management and authentication in VANETs while ensuring privacy preservation.