Details of Research Outputs

Vehicles participating in routing operations in vehicular ad hoc networks (VANETs) are required to periodically broadcast beacon messages. However, frequently broadcasting the vehicular information can pose a serious threat upon users' location privacy. While the exploitation of collective anonymity scheme on pseudonym change is an effective approach to protecting the location privacy of a target vehicle in VANETs, the exposure impact of the collective anonymity on privacy risk of a target vehicle has not been investigated yet. In this paper, we focus on improving anonymity level for a target vehicle in a collective anonymity scenario while achieving a high level of privacy exposure risk management. To achieve this, we first propose a pseudonym change scheme based on an assessment of the privacy exposure risk, aiming to manage and mitigate the privacy exposure risk of the target vehicle brought by exposed neighboring vehicles. Then we formulate an analytical model according to our proposed scheme in order to quantify the anonymity level of the target vehicle simultaneously updating pseudonyms with its neighbors. Simulation results show that our proposed scheme succeeds in promoting the size of anonymity set of the target vehicle with the growth in the number of its exposed neighboring vehicles. Meanwhile, with different setting parameters, our scheme retains effective performance compared to the random pseudonym change scheme.