SL-PPCP: Secure and Low-Cost Privacy-Preserving Communication Protocol for Vehicular Ad Hoc Networks

Vehicular Ad-hoc networks (VANET) enhance traffic efficiency and safety through wireless broadcasting of traffic-related messages. Secure communication, mutual authentication, privacy, and non-repudiation are, arguably, the most essential security requirements of vehicles in a VANET. To meet those security goals of VANET, we develop an efficient and secure communication protocol (SL-PPCP). The
signcryption
cryptographic primitive and the random oracle model are at the heart of the protocol, which accomplishes the requirement of public-key encryption and signature at a relatively low cost. For computation efficiency of the protocol, we design a systematic Offline/Online signcryption scheme with provable security. The scheme runs in two phases, namely, online and offline. The workload of the online phase is reduced by performing the costly operations, namely exponent, pairing and inversion, in the offline phase without knowledge of the message. The scheme proposed ensures existential unforgeability under a Chosen Message Attack, indistinguishability under an adaptive Chosen cipher-text attack, and insider security. For instance, the experimental results show that the computational time reduces approximately to 20.96%, 48.33%, 50.28% and 12.52% than of HOOSC, IP-HSC, MOHSC and LPPTE schemes respectively while performing the signcryption and unsigncryption of a single plaintext. Furthermore, the computational time for multiple ciphertext unsigncryption reduces significantly.