Computationally efficient privacy preserving anonymous mutual and batch authentication schemes for vehicular ad hoc networks

In the near future, it is envisioned that vehicular Ad hoc networks (VANETs) will be making use of long-distance communication techniques, such as cellular networks and Worldwide Interoperability for Microwave Access (WiMAX), to get instant Internet access for making the communication between vehicles and fixed road side infrastructure. Moreover, VANETs will also make use of short-distance communication methods, such as Dedicated Short-Range Communications (DSRC) and Wireless Fidelity (Wi-Fi) to perform short range communication between vehicles in an ad hoc manner. This Internet connection can provide facility to other vehicles to send traffic related messages, collisions, infotainment messages other useful safety alerts. In such a scenario, providing authentication between vehicle to infrastructure and vehicle to vehicle is a challenging task. In order to provide this facility, in this paper, we propose a computationally efficient privacy preserving anonymous authentication scheme based on the use of anonymous certificates and signatures for VANETs in making them an important component of Internet of Things (IoT) and the development of smart cities. Even though there are several existing schemes available to provide such anonymous authentication based on anonymous certificates and signatures in VANETs, the existing schemes suffer from high computational cost in the certificate revocation list (CRL) checking process and in the certificate and the signature verification process. Therefore, it is not possible to verify a large number of messages in a particular period in VANETs which would lead to increased message loss. Hence, we use a computationally efficient anonymous mutual authentication scheme to validate the message source as well as to verify the integrity of messages along with a conditional tracking mechanism to trace the real identity of misbehaving vehicles and revoke them from VANET in the case of dispute. In this paper, we also introduce an efficient anonymous batch authentication protocol to be used in IoT for Road Side Units (RSUs) to authenticate multiple vehicles simultaneously rather than one after the other such that the total authentication time can be dramatically reduced. This proposed scheme is implemented and the performance analysis shows that our scheme is more efficient in terms of certificate and signature verification cost, while preserving conditional privacy in VANETs.