This chapter addresses aspects of roadside unit (RSU)-assisted message authentication, in which resource-rich RSUs assist nearby vehicles to authenticate the messages they received. It proposes an RSU aided message authentication scheme, termed RAISE. In RAISE, each vehicle first anonymously authenticates itself to an RSU when approaching it within its transmission range. Then, a secure channel is established between the RSU and the vehicle.
The ns-2 simulator is used evaluate the performance of RAISE in terms of the message loss ratio, the message end-to-end delay, and the communication overhead. The chapter analyzes the security of the proposed scheme in terms of message integrity and source authentication, prevention of internal attack, replay attack resistance, and conditional privacy preservation. The RAISE protocol is advantageous because it needs less computation and communication overhead, and it also protects the vehicle’s location privacy.