Blockchain-assisted secure message authentication with reputation management for VANETs

Message authentication is of great significance for secure information sharing in vehicular ad hoc networks. Due to the lack of verification of message reliability and the high workload of identity checking, the propagation of unreliable messages and the increase in message loss rate are inevitable. To improve the reliability of message authentication, this work proposes a blockchain-assisted message authentication scheme based on a reputation evaluation mechanism. Specifically, blockchain is introduced to manage entity identities and certificates, and convenient certificate revocation management and vehicle identity authentication can be achieved by using smart contracts. Besides, a reputation evaluation mechanism is proposed to measure the credibility of messages, which can be integrated into message authentication to achieve efficient verification of message reliability. Performance analysis demonstrates that this scheme is more efficient than traditional signature-based authentication protocol in terms of computational cost, message delay, and data loss rate. Security analysis shows that this scheme can resist various common types of cyberattacks.