Cybersecurity and Supervisory Control: A Tutorial on Robust State Estimation, Attack Synthesis, and Resilient Control

This tutorial paper studies the effect of deception attacks on compromised sensors and actuators at the supervisory control layer of cyber-physical control systems. The problem is modeled and analyzed in the framework of the theories of state estimation, diagnosability, and supervisory control of discrete event systems, where discrete transition models are used. Both attacks and defense against attacks are considered. First, robust estimation and diagnosis in the presence of sensor attacks is analyzed. Next, the problem of synthesizing covert attacks is formulated and its solution is discussed in different contexts. Then, necessary and sufficient conditions on the existence of resilient supervisors are presented in the context of a general attack model. Finally, the problem of synthesizing supervisors that are resilient to covert attacks on sensors and actuators is studied. This paper accompanies the tutorial session on this topic presented at the IEEE CDC 2022.