An efficient privacy scheme for C-ITS stations.

In Cooperative Intelligent Transport Systems (C-ITS), vehicles and Road Side Units (RSU) exchange various messages about safety, traffic control, and weather conditions. These messages are broadcast to all neighbors. Each message should be authenticated and should protect users' privacy, mainly by hiding their locations. The authentication is achieved by signing messages using a private key related to the Pseudonym Certificate (PC), provided by a Trusted Authority (TA). The PC is delivered together with messages so that receivers can authenticate the messages. Privacy is ensured by changing PCs many times during a journey, so that trackers cannot get drivers' traces. This paper proposes a novel approach to manage PC switching periods between vehicles. The proposed method uses a Common PC (CPC) during a short period before switching to a new PC. Vehicles use the same shared PC during this period to sign their messages. Simulations have been conducted in an OMNET++ environment, showing significant improvement in privacy protection compared to well-known privacy schemes. [ABSTRACT FROM AUTHOR]