Efficient Anonymous Authentication and Group Key Distribution Scheme Based on Quantum Random Numbers for VANETs

Near-field communication in VANETs can effectively reduce communication overhead compared to peer-to-peer communication. However, there is still plenty of room for improvements to be made to ensure identity authentication privacy protection and to enhance the security and efficiency of key distributions during transmissions. Therefore, this paper proposes an anonymous identity authentication and group key distribution scheme based on quantum random numbers. In the proposed scheme, (1) anonymous credentials for vehicles are generated by a combination of random numbers on the vehicle side and random numbers in the TA, and mutual recognition of vehicles and roadside identity is achieved through the TA in the form of zero-knowledge proof, which achieves privacy protection for the vehicle during authentication. (2) A combined key generation method was devised. The roadside and the TA in this case jointly generate the group key. The TA uses a previously filled quantum key to encrypt the group session key parameter GSPc generated by its quantum random number generator to ensure security, and the roadside obtains the group session key parameter GSPr by calculating the anonymous credentials of all legitimate vehicles to achieve fast updates of the group session key. This scheme achieves forward and backward security while guaranteeing one-at-a-time encryption. The signaling and computation overheads were calculated, and the signaling overhead was reduced by nearly half. In addition, the group key issuance time was significantly reduced compared with other schemes. Through formal security analysis and experimental verification, the security and feasibility of this protocol were proved.