Certificate-Less Single-Use Pseudonym Scheme for Countering Trajectory Tracking Attacks in ITS

Periodic spatial-temporal safety messages play a significant role in supporting driving safety in Intelligent Transportation Systems (ITS). These messages include GPS coordination and are communicated between ITS nodes at small intervals to increase situational awareness and alleviate the risk of collision. However, even when pseudonyms are used rather than real IDs, an adversary can exploit the safety messages to deanonymize the trajectories of the ITS nodes. Specifically, the adversary can correlate collected pseudonyms to draw traces for node trajectory. This paper opts to tackle such vulnerability and proposes a novel certificate-less pseudonym scheme that withstands trajectory tracking attacks in ITS. Our scheme enables each node to autonomously generate a single-use pseudonym for every message while allowing a particular pseudonym to be generated by multiple nodes to increase false positive correlation of pseudonyms with nodes. Unlike competing approaches, we study the complete lifecycle of pseudonyms and show that our scheme is secure and lightweight. The simulation results demonstrate that our scheme considerably increases the anonymity of the ITS nodes and achieves a very low traceability rate.