An autonomous lightweight conditional privacy-preserving authentication scheme with provable security for vehicular ad-hoc networks.

Vehicular ad hoc network (VANET) is an emerging technology in wireless communications which has the prospect to improve traffic safety and efficiency, as well as reduce air pollution. The traffic-related messages transmitted between vehicles and roadside units must be signed and verified without revealing the real identities of the vehicles. However, an authorized trusted party must be able to obtain the real identity of a vehicle on a controversial message. Existing conditional privacy-preserving authentication (CPPA) schemes in VANETs either rely on a tamper-proof device or complex mathematical operations such as bilinear pairing and map-to-point hash function or cannot meet the privacy and security requirements in VANETs. In this work, we propose an efficient CPPA scheme for VANETs based on the elliptic curve cryptography without relying on any hardware device. The scheme satisfies the security and privacy requirements of VANETs, solves private key compromise problem, and provides countermeasure against privilege escalation. We show that the scheme is existentially secure against an adaptive chosen message and identity attacks in the random oracle model based on the hardness of the elliptic curve discrete logarithm problem. The performance results show that the proposed scheme is more efficient than previous schemes in VANETs. [ABSTRACT FROM AUTHOR]