Provable Secure and Lightweight Blockchain-Based V2I Handover Authentication and V2V Broadcast Protocol for VANETs

As one of the most valuable vehicle-based Internet of Things (IoT) applications, Vehicular Ad-hoc Networks (VANETs) have received extensive attention since it was proposed. In order to ensure the safety of VANETs and improve the communication efficiency between moving vehicles and different Roadside Units (RSUs), some handover authentication protocols for VANETs have been proposed. However, the existing protocols have some problems such as excessive computation overhead, untraceable malicious messages, and the inability to resist RSU captured attacks. To solve the above problems, we propose a blockchain-based protocol to achieve Vehicle to Infrastructure (V2I) authentication, V2I handover authentication, and Vehicle to Vehicle (V2V) broadcasting authentication. The advantages of our protocol are: (1) It achieves lightweight V2I handover authentication and V2V broadcast authentication, dynamic anonymity strategy and embedding strategy of pseudo-identity and vehicle feature are used to guarantee anonymity and traceability simultaneously; (2) The announcement can be broadcasted verifiably without the help of transportation infrastructure (e.g., RSU) or the Trusted Authority (TA); and (3) The Physically Unclonable Functions (PUF) technology is used to resist RSU captured attacks. We use formal security proof under random oracle model to prove the security of the proposed protocol. Compared with related V2I handover authentication protocols, our protocol can resist RSU captured attacks and other various known attacks. The sum of first and handover authentication efficiency of our protocol is 37.93% higher than the previous most effective protocol, while maintaining the same level of communication and storage costs.