ID-PPA: Robust Identity-Based Privacy-Preserving Authentication Scheme for a Vehicular Ad-Hoc Network.

The rapid evolutions in wireless communications as well as the urgent demand for reducing traffic jams and road fatality rates lead to appear Vehicular Ad-Hoc Networks (VANETs). There is a necessity to ensure that any connection within VANETs should be secure against cyber-attacks. This is due to the fact that data transmission through any open-access environment may lead to different network attacks. Therefore, the identity-based privacy-preserving authentication scheme (ID-PPA) was proposed in this paper in order to resolve different issues that are related to the security and privacy in VANETs. Recently, there are a lot of ID-based schemes of security in VANETs have been introduced. However, these schemes could suffer from many problems. Indeed, ID-PPA scheme overcomes these problems that are found in ID-based schemes. However, ID-PPA scheme avoids key escrow problems and impersonation attacks that are found in other ID-based schemes. Moreover, it provides an efficient process to trace and revoke any malicious vehicle in the network. In the ID-PPA scheme, the first and second phases describe the initialization of system parameters and vehicle registration. The third phase is responsible for creating mutual authentication between vehicle and roadside unit (RSU). It is also responsible for generating a set of signatures for each vehicle by the RSU. The beacon generation and the verification processes are explained in the last phase. The security analysis indicates that the ID-PPA scheme can satisfy all the security and privacy requirements, and can avoid the well-known attacks. Finally, a comparison between our scheme and other ID-based schemes shows that the cost of computation without using batch verification, which may cause problems in some cases, is significantly reduced using the ID-PPA scheme.