An Output Feedback Game-Theoretic Approach for Defense Against Stealthy GNSS Spoofing Attacks

We employ a game-theoretic approach to mitigate stealthy spoofing attacks on an aerial cyber-physical system. The attacker's objective is to drive the vehicle away from its nominal trajectory while misleading the system operator of the adversarial deviation. We characterize this as a dual actuation-deception attack; the former involves corrupting the vehicle's actuating input, and the latter is done by spoofing the measurable output; that is, the acceleration effort and the Global Navigation Satellite System (GNSS) sensor reading, respectively. The attack is designed to be stealthy, implying that its effect on the system's trajectory is indiscernible from that of a naturally occurring disturbance. The defender aims to counter such an attack and steer the aerial vehicle back towards its nominal path. We couple receding horizon control and game-theoretic methods to derive optimal attack and defense policies.