Switching-Based Moving Target Defense Control Against Cyberattacks

This article addresses the issue of security in cyber–physical systems (CPSs) in the context of malicious actuator false data injection (FDI) attacks. Building on a stochastic physical dynamics model, the proposed approach distinguishes itself by employing a moving target defense (MTD) strategy to enable proactive protection, which is an aspect rarely addressed in existing related works. The system model is formulated as a family of controllable submodels based on controllability. These controllable submodels are regarded as moving targets. A residual-based attack detector is introduced to justify whether an attack occurs or not. When an alarm is triggered, the current running controllable submodel is switched to another controllable one. Furthermore, an MTD-based security controller is devised to proactively mitigate actuator attacks. Sufficient conditions for the design of security control gains are formulated, using which the CPSs can preserve the mean-square exponential stability with the desired disturbance rejection level. Finally, the effectiveness of the proposed control strategy is demonstrated through a comparative simulation based on a practical physical system.