A Blockchain-assisted lightweight privacy preserving authentication protocol for peer-to-peer communication in vehicular ad-hoc network

Vehicular Ad-Hoc Network (VANET), provides considerable real-time traffic information services that enhance safety and traffic effectiveness. However, as most of the VANET systems are centralized in nature prone to single-point failure, and vulnerable to attacks there will be reasonable delay in communication. In this paper, a lightweight privacy-preserving authentication scheme for peer-to-peer communication using blockchain (DLPA) while considering the resource-constrained nature of VANET is proposed. We have designed and deployed smart contracts using public blockchain to resist the vehicle impersonation attack, to identify illegal vehicle's identity and thereby non-repudiation will be achieved. Vehicle-to-Vehicle (V2V) authentication and peer-to-peer communication are attained without the involvement of a Trusted Authority (TA) and to eliminate the trusted third party who is responsible for generating the key. Furthermore, DLPA has achieved handover authentication of vehicles so that vehicles need not be re-authenticated when they enter into a new Road Side Unit (RSU) limit. The proposed scheme is implemented in different Ethereum-powered test networks using Remix IDE to demonstrate the feasibility and to analyze the performance of the smart contract in terms of transaction cost and execution cost. In addition to that, security proof and analysis are performed to unveil that our proposed scheme preserves the privacy of the communicating parties, semantic security of the session key, and resistance against various known threats and attacks. Finally, the performance analysis of the scheme is done by calculating the communication and computation costs. The computation cost for our DLPA scheme for V2V authentication is 0.27461 ms and for V2RSU authentication is 0.15622 ms. The communication cost for both V2V and V2RSU authentication is 640 bits. While analyzing the result, the proposed protocol has a minimal cost when compared with other blockchain-based authentication schemes in VANET.