A Blockchain-based Privacy-Preserving Authentication Scheme with Anonymous Identity in Vehicular Networks

With the rapid development of mobile network technology, Vehicular ad-hoc Networks (VANETs), one of the most promising applications in the smart transportation systems, have drawn widespread attention. Unfortunately, authentication and privacy protection of users have seriously restricted the development of VANETs. The past works used to allow a centralized trusted authority to distribute identity information and maintain the operation of the whole system lacking of distributed and decentralized security. In this paper, we propose an authentication scheme based on consortium blockchain with anonymous identity in VANETs. First, when authenticating and providing services, our scheme allows the vehicles using Pseudo IDs obtained from the Road Side Unit (RSU) to protect the privacy of the vehicles preventing location tracking due to disclosure of information. Second, based on consortium blockchain technology, it provides a decentralized, secure and reliable database for storing certificates and the pointer to storage location, which is maintained by the multiple Trusted Authorities (TAs) and RSUs. Furthermore, in the revocation, the RSUs are able to determine promptly that the vehicle has been revoked by adding a revocation tag to the pseudo ID instead of searching the entire certificate revocation list (CRL). According to the security and performance analysis, our scheme owns higher security and efficiency.