A Novel Proactive Defense Strategy Design for Cyber-Physical Systems in the Presence of FDI Attacks

This paper proposes a novel proactive defense strategy tailored to address false-data-injection (FDI) attacks in cyber-physical systems (CPSs). Specifically targeting FDI attacks, which compromise system integrity by manipulating sensor and control inputs, watermarking and moving target defense (MTD) mechanisms are integrated. The watermarking signal is designed to encrypt control inputs, enabling the detection of FDI attacks by exploiting inconsistencies between injected false data and the known watermark pattern. Meanwhile, the MTD strategy, characterized by mode-dependent average dwell time (MDADT), dynamically alters system parameters to obscure attack surfaces. Sufficient conditions for robust H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> disturbance attenuation in switched systems under these defenses are derived. Furthermore, tailored response mechanisms are formulated to mitigate attack impacts on system performance, with quantitative comparisons demonstrating the efficacy of the proposed methods against FDI attacks. Numerical simulations validate the robustness and superiority of the hybrid defense strategy in scenarios involving FDI attacks.