HEPPA: Highly efficient privacy preserving authentication for ITS

Abstract

Intelligent Transport Systems (ITS) play a very important role to increase the safety and to decrease road congestions. These systems require secure communication between both infrastructure and vehicles. In this paper, we construct a three-factor highly efficient privacy preserving authentication (HEPPA) protocol between vehicles and road side units (RSUs) using a telematics device enabling biometric operations, bonded to the vehicle. Broadcast messages sent by the vehicles only contain symmetric key cryptographic operations. Elliptic curve cryptographic operations are used for the key establishment and renewal between the vehicles and RSUs. Due to the clever construction of the pseudonyms, the RSU listening the broadcast messages is able to directly detect malicious behaviour and to alert the neighbouring vehicles. Moreover, no certificate revocation lists need to be stored at the vehicles and no list of key material is required at the RSUs. The real identity of malicious behaving vehicles and corresponding drivers can be revealed by a cooperation among RSU and certificate authority (CA). Consequently, attacking an RSU will not leak privacy related information. What is more, the tamper resistant hardware in the telematics device only stores user specific and temporary key related information, so no global system security parameters.