Evaluation of a Pseudonym Change Scheme using LSH for Location Privacy in V2X Communication

In Vehicle-to-Everything (V2X) communication, vehicles transmit their information to surrounding vehicles and infrastructures for traffic safety and efficiency. However, vehicle anonymity in communications is important because location privacy is threatened when communications are eavesdropped and traced by malicious attackers. The method of periodically changing pseudonyms instead of using actual identification has been considered to provide anonymity. However, anonymity is significantly reduced when the number of vehicles changing pseudonyms simultaneously is insufficient, or when the vehicle trajectory is easily predictable. In this paper, we propose a cooperative pseudonym change scheme among vehicles with similar vehicle information extracted using Locality Sensitive Hash-ing (LSH), aiming to achieve higher vehicle anonymity. We analyze the anonymity of the proposed scheme in our mathematical model under lim-ited circumstances and evaluate it in comparison with existing pseudonym change schemes.