Identity-based message authentication scheme using proxy vehicles for vehicular ad hoc networks

Message authentication verifies the identity of the sender vehicle, ensuring it in between vehicles and Road Side Units (RSU) is an essential part of Vehicular Adhoc Networks. Signature verification in RSUs will be troublesome if a large number of vehicles enters in its region at the same time. In such cases the efficiency of the RSUs will be affected due to high computational overhead. To address this issue, proxy vehicle based message authentication scheme (ID-MAP) is proposed by Asaar et al. (ITVT 67: 5409, 2018). It uses proxy vehicles to reduce the overheads of the RSU by verifying multiple messages at the same time. Even though it deals with the efficiency issues of RSU, the computational cost of signature generation is high. Since the ability of a vehicle to act as a proxy vehicle is based on the number of signed messages, it has a major impact. It also cannot guarantee privacy preservation and hence it is insecure against attacks based on privacy preservation. It also has other drawbacks like storage issues and high overheads. Hence, a new identity based message authentication using proxy vehicles is proposed in this paper. Elliptic Curve Cryptography based scheme is used without pairings for message authentication. Proxy vehicles will verify multiple messages from vehicles through batch verification and send the result to the RSU. The identity of multiple proxy vehicles will be verified by RSU, it can also cross check the correctness of the received result. Thereby RSUs can verify a large number of messages at the same time with the help of proxy vehicles. Security analysis shows that if each proxy vehicle verifies 300 messages of its neighbor vehicles, then with the help of proxy vehicles an RSU can verify 226,244 messages per second which is 40% less than that of ID-MAP scheme. It also shows that the computational cost to generate a signature in the proposed scheme is 50% less than that of ID-MAP scheme.