Token-based Lightweight Authentication Scheme for Vehicle to Infrastructure Communications

Abstract

Vehicular Ad Hoc Network (VANET) has drawn extensive attention in recent years due to the benefits it offers ranging from non-safety applications such as, toll services, internet access and parking payment to safety applications such as lane keeping assistance and post-crash notification. VANET consists of two types of communications which are V2I and V2V to broadcast messages about the road traffic to ensure safety for road users. The communication channel in VANET is vulnerable to attacks which must be resolved before network deployment. Timely source authentication, non-repudiation and message integrity are essential security requirements for VANETs. Previous studies have used Public Key Infrastructure (PKI) to fulfil the security requirements. However, the use of PKI based schemes introduces high communication and computation overheads which is not suitable for time critical applications in VANETs. Hence, in this paper we propose a lightweight authentication scheme based on Schnorr signature and authentication tokens for V2I communications. Through extensive simulations we show that the proposed scheme is efficient and has lower computation and communication overheads due to the utilisation of Schnorr signature which has a very low signature size and does not require high computation operations compared to ECDSA. Also we analyse our scheme to show it satisfies the security requirements of VANETs.