Resilient Control of Cyber-Physical System Using Nonlinear Encoding Signal Against System Integrity Attacks

In this paper, we propose an attack resilient control structure for a cyber-physical system (CPS) to enhance the CPS security against stealthy system integrity attacks that manipulate the state of the physical plant while undetected. With the help of nonlinear encoding/decoding components, the proposed structure can detect stealthy attacks and preserve the nominal performance without considering attacks. Meanwhile, for avoiding the eavesdropping of transmitted signals used to synchronize encoding/decoding components between the physical and cyber layers, the chaotic oscillators are employed for the secure communication. The resilience against the malicious attacks and the robustness under the time delay and nonlinear components of the proposed CPS structure are investigated in view of input-to-state stable (ISS) framework. Simulations for Quadruple-Tank Process are performed to validate the performance of the proposed method.