Selecting basic safety messages to verify in VANETs using zone priority

Basic Safety Messages (BSMs) are an important message type used in safety applications in VANETs. When a vehicle receives a BSM it should verify the signature using cryptographic techniques. However as BSMs are periodically broadcast by all vehicles, the number received per second will exceed the verification capability of on-board units in high density traffic areas. We propose a flexible, zone priority-based scheme to select the most important BSMs to verify first. We consider the zone of the sending vehicle (i.e. vehicles in opposite direction which have already passed as least important), as well as position, acceleration and velocity of vehicles in ranking BSMs. Compared to existing techniques that use random or distance-based verification, simulation results show our scheme can better select the more important messages to verify first.