An Improved Lightweight Identity Authentication Protocol for VANET

Abstract

Recently, Li et al. proposed a lightweight identity authentication protocol (LIAP), in which a unique authentication sequence was firstly shared by a vehicle and the RSUs, then a dynamic secret session process (DSSP) was implemented to achieve the mutual authentication. However, Zhou et al. proved that LIAP was vulnerable against the location privacy tracking attack and the parallel session attack, and proposed an improved protocol. In this paper, Li’s scheme and Zhou’s scheme are analyzed to be impractical. Moreover, they are vulnerable against the impersonation attacks when some RSUs are compromised by the adversary. Accordingly, an improved version of LIAP is proposed, in which an asymmetrical dynamic secret session process (ADSSP) method is used to replace the DSSP, and a novel distribution model of the authentication sequences is implemented to solve the problem of feasibility. Especially, the security of the proposed protocol is enhanced greatly to resist the impersonation attack. Security and performance analysis shows that the improved version not only resists the known various attacks, but also is more efficient and practical.