Privacy-Preserving Route Reporting Schemes for Traffic Management Systems

In this paper, we propose privacy-preserving route reporting schemes for traffic management for both infrastructure-supported and self-organizing vehicular ad hoc networks (VANETs). Using only pseudonyms and anonymous authentication to conceal the real identity of the drivers cannot fully preserve the drivers' privacy because the reported future positions can be used to link pseudonyms and identify the drivers, e.g., from the locations they visit. Motivated by the fact that traffic management systems do not need to know the vehicles' individual routes and the total number of vehicles in each road segment would suffice, the proposed schemes aggregate the vehicles' routes. Countering the collusion attacks is usually hard, particularly in a self-organizing setting. The concept we use to mitigate the attack is that one vehicle is not trusted to run the scheme because it can be curious to know the drivers' routes, but these schemes are run by multiple vehicles. Our ns-2 simulation results and analysis have demonstrated that our schemes can preserve the drivers' privacy with acceptable overhead.