C-ITS PKI protocol: Performance Evaluation in a Real Environment

Abstract

In the near future, vehicles and roadside units (RSU) will communicate and cooperate by broadcasting V2X messages over the vehicular network (IEEE 802.11p). These messages are used by safety applications to improve road safety and traffic efficiency. However, those messages could also be used in a malicious way to track vehicles. Therefore, to guarantee drivers privacy, vehicles use pseudonym identities (or certificates) provided by a Public Key Infrastructure (PKI). During a trip, vehicles frequently change of certificates to make tracking much more difficult. They thus need to reload their certificates pool by requesting new ones to the PKI. In this paper, we evaluate the performance of the PKI protocol regarding the reloading of certificates. We ran several tests while driving in order to quantify the number of certificates that can be reloaded from the PKI at different speeds. The obtained results show that 1) the end-to-end latency between a requesting vehicle and the PKI is non-negligible and 2) as speed increases, the number of successfully reloaded certificates decreases.