An Efficient and Physically Secure Privacy-Preserving Key-Agreement Protocol for Vehicular Ad-Hoc Network

The popularity of vehicles promotes the evolution of smart cities. This development makes vehicular ad-hoc network (VANET) a widely used inter-vehicular communication to obtain information about road conditions, speed, vehicle location and traffic congestion. Such a public network is vulnerable to different security threats. Overall, the security of private data in VANET is a critical task. It has been observed that various authentication protocols have been devised for VANETs. However, most of the proposed protocols are not secure and reliable because of different security threats, including denial of service, replay, forgery and impersonation attacks, etc. Furthermore, the existing protocols used extra communication overhead and computational cost, so they become infeasible for resource-constrained environments. In this article, we design a lightweight and secure privacy-preserving key agreement protocol for VANETs using the hashing technique, which provides an efficient and secure data transmission mechanism over a public communication channel. Detailed security analysis shows that the proposed protocol is secure against various attacks. To evaluate the performance of the protocol, we simulate key cryptographic operations of vehicles, a roadside unit, and a trusted party agent on Arduino, low-end and high-end devices, respectively. The experimental results show that compared with the other related protocols, the computational cost and communication overhead of our protocol are reduced on average by 8.797% and 22.06 %, respectively. Additionally, simulation results on NS3 show that our protocol consistently achieves a packet delivery ratio higher than 99.91 %. Therefore, our protocol is secure and reliable for VANET environment.