Towards resilient supervisors against sensor deception attacks

We consider feedback control systems where sensor readings may be compromised by a malicious attacker intent on causing damage to the system. We study this problem at the supervisory layer of the control system, using discrete event systems techniques. We assume that the attacker can edit the outputs from the sensors of the system before they reach the supervisory controller. In this context, we formulate the problem of synthesizing a supervisor that is robust against a large class of edit attacks on the sensor readings. We solve this problem using a new methodology that improves upon prior work on this topic. The solution methodology is based on the solution of a partially observed supervisory control problem with arbitrary control patterns. We also provide results on the existence of a supremal robust supervisor.