A Pseudonym Management System to Achieve Anonymity in Vehicular Ad Hoc Networks

In this paper we propose a framework for providing anonymity to communicating cars in VANETs. The anonymity is accomplished based on a system of pseudonym generation, distribution, and replenishing. The road side units (RSUs) play a key role in the framework by receiving the originally generated pseudonyms from the trusted authority, and then distributing pseudonym sets to cars while shuffling the sets amongst themselves to maximize anonymity. The pseudonym distribution process among the RSUs and to the vehicles is highly adaptive to accommodate the needs of the vehicles. We develop a distributed optimization algorithm for the shuffling process and a novel mechanism for cars to change their pseudonyms. Experimental evaluations based on ns3 simulations demonstrate the effectiveness of the framework through showing relatively high values of the used metric, namely the anonymity set.