On the performance evaluation of vehicular PKI protocol for V2X communications security

Cooperative Intelligent Transportation Systems (C-ITS) is an ongoing technology that will change our driving experience in the near future. In such systems, vehicles and Road-Side Units (RSU) cooperate by broadcasting V2X messages over the vehicular network (802.11p). Safety applications use these data to detect dangerous situations on time and avoid them. The security of V2X communications is based on the use of a vehicular Public Key Infrastructure (PKI) that delivers digital certificates to vehicles and RSU. Vehicles frequently change their certificate in order to make tracking more difficult and thus preserve drivers privacy. In this paper, we evaluate the performance of our PKI regarding the reloading of certificates by comparing two communication profiles (with and without V2X security). We developed a Proof-of-Concept (PoC) with real implementation of the PKI protocol and the embedded system. The obtained results show that the end-to-end latency between a requesting vehicle and the PKI is non-negligible. We then discuss and propose optimizations that can be done to improve the performance of the system.