Modeling Sybil attacker behavior in VANETs

Vehicular Ad-Hoc Networks (VANET) is mainly designed to provide human safety, traffic management, and infotainment services. The decision how to react on information received from other vehicles always has to be made locally. This made attackers to abuse the information and it will endanger the security of the system and human lives. In VANETs Sybil attack is an identity forging attack that a malicious node impersonates several other nodes in order to disrupt the proper functioning of VANET applications. In this paper we discuss and motivate the needs for real traffic simulation with standard network simulation and explain the attack models for an individual Sybil attacker. We consider that the attack model can be changed in each traffic scenario and sophisticated movement path such as urban traffic model having a potentially high influence compared to uniform highway traffic model. Also we simulate and compare attacker models in two positions: near the source and near the destination of data packet sending. The risk analysis shows that the most serious threat arises from a Sybil attacker that distributed forged warning messages near the source of packet sending because of the number of hops between nodes.