Mix-zones optimal deployment for protecting location privacy in VANET

A promising approach to protect driver's location privacy in vehicular ad hoc network (VANET) suggests vehicle changing pseudonyms in regions called mix-zones, where the adversary cannot eavesdrop the vehicular communication. How to deploy mix-zones in a large city is a challenge problem and has not been well addressed in previously reported works. In this paper, we propose a statistics-based metric for evaluating the effectiveness of a mix-zone and selecting mix-zone candidates in term of privacy requirement. Furthermore, a cost-efficient mix-zones deployment scheme is presented to guarantee that vehicles at any place could pass through an effective mix-zone in certain driving time, and the extra overhead time of adjusting routes to across the mix-zone is small. Extensive simulations demonstrate that the proposed evaluation metric is viable under various traffic scenarios while the deployment plans generated by our scheme in a real-world map make drivers have more chances to pass through mix-zones on road.