A Hybrid Blockchain-Based Privacy-Preserving Authentication Scheme for Vehicular Ad Hoc Networks

As the inevitable mode of the future intelligent transportation system, VANET still exists vehicle access authentication computational overhead, handover authentication inefficiency in the context of continuous development, simply using the traditional VANET architecture has been unable to adapt to the new complexity. Therefore, a hybrid blockchain-based privacy-preserving authentication scheme is proposed. Instead of using a single chain, the scheme combines the consortium and private chains, retaining the decentralization and high security of the consortium chain while leveraging the advantages of faster transactions, lower costs, and higher privacy in the private chain. Importantly, short signature technology and homomorphic encryption technology are proposed to further improve the efficiency of entity communication and protect the delivery of private data, respectively, while pre-authentication mechanism is used to further accelerate the cross-domain authentication of vehicles. The security analysis demonstrates the good privacy protection and attack resistance of this scheme. In addition, performance simulations and evaluations show that the proposed scheme requires the least computational and communication overhead compared to other schemes. It also performs better in terms of authentication delay and packet loss rate. Finally, the availability of the proposed scheme is explained through throughput and transaction cost analysis.