An Active Detection Method for Generalized Replay Attacks Using Multiplicative Watermarking

Cyber attacks usually bring serious performance loss and even system instability of networked control systems (NCSs), however attack detection provides a path to guarantee system security. Therefore, the main objective of this paper is to propose an effective active detection method for generalized replay attacks (GRAs) using multiplicative watermarking (MW). Firstly, the characteristic of GRAs against NCSs is analyzed. Secondly, sufficient condition of the detectability for GRAs is provided, where the relationship among the detectability, GRAs intensity, MW parameters and attack initial instant is revealed. Thirdly, multiplicative distortion power (MDP) is employed to quantify system performance loss from GRAs, and it is proved that MDP of undetected GRAs against NCSs is bounded. Finally, numerical simulations confirm the feasibility and effectiveness of the proposed method.