Pseudonym Based Mechanism for Sustaining Privacy in VANETs

This paper addresses the problem of sustaining the privacy of a vehicle in a vehicular ad hoc network (VANET). In a VANET, vehicles broadcast information as they move on the road. The location of a vehicle can estimated using localization techniques and its identity can be read from its messages. A link can be established between the physical vehicle through localization and its identity is a threat to privacy. This localization is not accurate and a vehicle can hide in the crowd of neighborhood vehicles. Further to avoid getting tracked, vehicles use pseudonyms and update these pseudonyms as they transmit. To avoid depletion of pseudonym pool, pseudonym update must be performed only when required. In this work, a strategy has been formulated for pseudonym update to sustain privacy when a vehicle is being observed by an adversary with different capabilities. Results indicate that updating pseudonyms in accordance to the strategy maximizes the privacy of a vehicle.