NECPPA: A novel and efficient conditional privacy-preserving authentication scheme for VANET
Abstract Vehicular Ad-hoc Networks (VANETs) are growing in recent decades providing real-time communication between vehicles for a safer and more comfortable driving. The main idea of VANET is the fact that vehicles can broadcast ad-hoc messages such as traffic incidents and emergency events. The security of such networks is quite critical. This paper firstly reviews and analyzes the main authentication schemes in VANET to compare their pros and cons. We then propose a new authentication scheme which provides secure communications in VANET. Our proposed scheme is a combination of Road Side Unit Based (RSUB) and Tamper Proof Device Based (TPDB) schemes. A novel idea in NECPPA is to let the keys and the main parameters of the system be stored in the Tamper Proof Device (TPD) of Road Side Units (RSUs). Since, there is always a secure and fast communicational link between TA and RSU, inserting TPD in RSUs is much more efficient than inserting them in OBUs. It also should be noted that due to the fact that in NECPPA scheme, the main key of TA (master secret key) is not stored in all OBUs, the compromise or hacking a single OBU does not threaten the whole network despite what happens in TPDB scheme which makes the whole vehicles re-register and change their secret keys. In addition, our proposed scheme is much more cost efficient compare to other on-line RSUB schemes, as it does not need the establishment of on-line RSUs in the whole roads. We also prove the security of our scheme with formal proof and ProVerif automatic analysis tool. The simulation results show that the efficiency and performance of our proposed scheme in VANETs have improved compare to other schemes.