Secure privacy and distributed group authentication for VANET

Vehicular Ad Hoc Network (VANET) has evolved to complement Intelligent Transportation System (ITS) for communicating safety messages while driving on the road and it faces challenges such as certificate management and privacy preservation. In this paper, a distributed authentication scheme called as Group Authentication Protocol (GAP) is proposed to resolve the most conflicting security requirements such as group authentication and conditional privacy. GAP uses session based pseudonym to support anonymous communication. The proposed batch verification scheme as a part of the protocol poses a significant reduction in the message delay. Furthermore, it enables the vehicles to verify a large number of messages in the case of high vehicular density and also improves message loss ratio. Trusted third party called Trusted Authority has the complete control of tracing the vehicles both benign and misbehaving vehicles.