A Watermark Detection Method for Approximate Replay Attacks Based on State Compensation

Approximate replay attacks are a form of attacks obtained by parameter selection of the generalized replay attack model, which seriously threatens the security of cyber-physical system (CPS). To address the detection problem of approximate replay attacks, this paper proposes a watermark detection method based on state compensation. The adverse effect of the watermark signal added in the control channel on the system state estimation can be eliminated completely by the designed state compensation structure with an auxiliary estimator. Simulation experimental results show that the detection method proposed in this paper can effectively detect approximate replay attacks.