International Association
for Cryptologic Research

Vehicle-to-everything (V2X) communication is the key enabler for emerging intelligent transportation systems. Applications built on top of V2X require both authentication and privacy protection for the vehicles. The common approach to meet both requirements is to use pseudonyms which are short-term identities. However, both industrial standards and state-of-the-art research are not designed for resource-constrained environments. In addition, they make a strong assumption about the security of the vehicle's on-board computation units. In this paper, we propose a lightweight auto-refreshing pseudonym protocol LARP for V2X. LARP supports efficient operations for resource-constrained devices, and provides security even when parts of the vehicle are compromised. We provide formal security proof showing that the protocol is secure. We conduct experiments on a Raspberry Pi 4. The results demonstrate that LARP is feasible and practical.