Exploiting Wireless Channel Randomness to Generate Keys for Automotive Cyber-Physical System Security

Modern automotive Cyber-Physical Systems (CPSs) are increasingly adopting wireless communications for Intra-Vehicular, Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) protocols as a promising solution for challenges such as the wire harnessing problem, collision detection, and collision avoidance. Regrettably, this new trend results in new security vulnerabilities that can put the safety and privacy of the automotive CPS and passengers at great risk. In addition, automotive wireless communication security is constrained by strict energy and performance limitations of Electronic Controller Units (ECUs) and sensor nodes. As a result, the key generation and management for secure automotive CPS wireless communication is an open research challenge. This paper aims to help solve these security challenges by presenting a practical key generation technique based on the reciprocity and high spatial and temporal variation properties of the automotive wireless communication channel. To validate the practicality and effectiveness of our approach, we have conducted separate real- world experiments with automobiles and with RC cars. Lastly, we demonstrate through simulations that we can generate keys with high security strength (keys with 67% min-entropy) with up to 10X improvement in performance and 20X reduction in code size overhead in comparison to the state- of-the-art security techniques.