Cluster-Based and Multi-Level Blockchain-Based Secure Authentication Scheme for IoV

In order to solve the centralized authentication characteristics of high mobility and low efficiency in the Internet of Vehicles ($\mathbf{I o V}$), this paper proposes a secure authentication scheme based on clustering and multi-level blockchain (CB-MBCSA). In this scheme, the Root Trusted Authority RTA stores all vehicle information to maintain the public blockchain RTAB (Root Trusted Authority Blockchain); the Local Trusted Authority LTA is responsible for maintaining the private blockchain LTAB (Local Trusted Authority Blockchain) that implement collaborative authentication and block validation among clusters; Then, a time-sensitive trust assessment scheme is adopt to improve the selection of Cluster Head (CH), which is responsible for local authentication and block generation. In this scheme, a consensus algorithm Proof-of-Work (PoW) is used to construct the blockchain, Practical Byzantine Fault Tolerance (PBFT) is introduced in the authentication process, and encrypted information is transmitted between the blockchain. Finally, the performance of the proposed transmission protocol is evaluated using NS-2 Simulation Platform. The simulation results show that CB-MBCSA has advantages in terms of storage and throughput under denial-of-service attacks.