An analysis of anonymity on capacity finite social spots based pseudonym changing for location privacy in VANETs

Location privacy is one of the prime goal of the quality of privacy in vehicular ad hoc network (VANET) and essential for the VANET's great prosperity. Constantly changing pseudonyms is one of general accepted ways to protect location privacy in VANET, but many strategies that pseudonyms are changed in an improper situation may lead to be invalid or some solutions are lack of taking the real scene into consideration. To improve the effectiveness of the issue, in this paper, we propose a valid and actual strategy that vehicles change pseudonyms at capacity finite social spots to achieve the location privacy by taking the anonymity set size as the location privacy metric. We first introduce the social spots where lots of vehicles gather together at a free and capacity finite parking lot near a shopping mall, and then we develop an anonymity set analytic model closer to the reality quantitatively investigate the location privacy that is achieved by the proposed strategy.