An analysis of anonymity for cooperative pseudonym change scheme in one-dimensional VANETs

Frequently changing pseudonyms is one of commonly accepted approaches to protect location privacy in Vehicular Ad hoc NETworks (VANETs), but most pseudonyms change schemes based on vehicular individual behavior are inefficient and the level of anonymity provided by these schemes is difficult to be analyzed. In this paper, we discuss how Cooperative Pseudonym Change (CPC) scheme enhances anonymity and develop an approximate analysis model for the scheme in one-dimensional VANETs to quantify the level of anonymity where vehicles are uniformly distributed on road. The accuracy of this model is verified by a set of simulations, and the results show that the enhanced anonymity rate of CPC scheme over Non-Cooperative Pseudonym Change (NCPC) scheme has a trend of first increase and then decrease with the increase of the average number of neighbors of the target vehicle.