Sybil attack detection in vehicular ad hoc networks (VANETs): a comprehensive survey

There are more vehicles on the road with the expansion of the world's population and the growth of the economy. With an increased number of vehicles, the chances of incidents and fatalities on the roads also rise. VANETs have great potential for reducing the risk of accidents and the consequent number of road deaths through the implementation of vehicular communications. Besides allowing road operators to observe any unruly behavior and take action promptly, VANETs have design-related, routing, communication, and safety issues to consider. The use of wireless communication brings with it the risk of these networks becoming prone to various kinds of security attacks, such as acquiring multiple identities by a vehicle or RSU station, popularly known as the Sybil attack. This vulnerability may result in a malicious vehicle sending fabricated messages over the congestion of roads, imminent road accidents, road closures, etc., to deceive drivers into routing via other routes and exposing them to unfortunate incidents. This paper presents a profound study of techniques and methodologies adopted for the detection and mitigation of Sybil attacks within VANET networks. The systematic classification of existing approaches is further done with a detailed analysis concerning detection mechanisms, deployment strategies, and evaluation metrics.