Fake Beacon: A Pseudonym Changing Scheme for Low Vehicle Density in VANETs.

The Vehicular Ad-hoc Network is formed from a collection of communicating vehicles so that they can share information in order to avoid traffic accidents or congestion. However, this system requires vehicles to share sensitive information which may lead to privacy issues. To solve this, pseudonym and correlating pseudonym changing schemes based on mix-zones are used instead of the real Identification (ID) labels for authentication. Despite this, an adversary can still determine vehicle traces, for instance, using a beacon-based vehicle tracking algorithm. The situation is even worse when vehicle densities are low. We propose a fake beacon pseudonym changing scheme suitable for low vehicle density situations. We adapt Road Side Unit (RSU) mix-zones to generate fake beacons imitating real vehicles so that the vehicle density and complexity are fictitiously increased. We implement a traffic simulation and an adversary attack algorithm to evaluate the performance of our scheme. According to the results, the success rate of the adversary recovering vehicle traces drops over 50% compared with a traditional mix-zone scheme. The performance is not influenced if vehicle overtaking is allowed. In addition, the resource consumption can be reduced without significantly compromising the performance.