Robust corrective control against fundamental and non-fundamental mode attacks with application to an asynchronous digital system

This article presents a robust model matching corrective control scheme for input/state asynchronous sequential machines (ASMs) vulnerable to both fundamental and non-fundamental mode attacks. Specifically, when non-fundamental mode attacks occur, ASMs undergo unauthorized state transitions in their transient behaviors, reaching faulty states. The attack outcome is exacerbated if non-fundamental mode attacks occur during the procedure of model matching by the controller. We address the necessary and sufficient condition and design procedure for a state-burst-feedback corrective controller that eliminates the adverse effect of both fundamental and non-fundamental mode attacks, while matching the stable-state behavior of the closed-loop system to that of a reference model. To demonstrate the synthesis of the controller and applicability of the proposed scheme, a practical ASM termed the payload data manager and the corrective controller are implemented on field-programmable gate array (FPGA) circuits. Experimental results are provided on model matching and robust corrective control overcoming both fundamental and non-fundamental mode attacks.