Pseudonym Changing for Vehicles in VANETs: A Game-Theoretic Analysis Based Approach

As a prime target of the quality of privacy in vehicular ad hoc networks (VANETs), trajectory privacy is imperative for VANETs to fully flourish. Although mix-zone based on several pseudonyms provides a promising solution for trajectory privacy in the VANETs, if the vehicles changed pseudonym in an improper mix-zone or frequently changed the pseudonym in each passing mix-zone, such a solution may result in unacceptable situation where the privacy is not improved but the huge cost is incurred. To cope with the issue, in this paper, we present an effective pseudonym changing game G to achieve a tradeoff between cost and privacy. Firstly, pseudonym changing game is established by analyzing the relationship between pseudonym changing, cost, and privacy. Then, according to the game Nash equilibrium, pseudonym changing mechanism that vehicles autonomously determine whether to change pseudonym is designed. Finally, we analyze performance advantages of the pseudonym changing mechanism through simulation experiments.