Security analysis for cyber-physical systems under undetectable attacks: A geometric approach

In this paper, the security issues of cyber-physical systems under undetectable attacks are studied. The geometric control theory is used to investigate the design, implementation, and impact evaluation of undetectable attacks. First, a feedforward-feedback structure for undetectable attacks is proposed, which provides a designable form for an attack to be undetectable. The corresponding attack strategy is designed via pole placement in the weakly unobservable subspace of the attacked system. Then, the security analysis of several common undetectable attacks injected from actuators, sensors, and the coordinated of the two is discussed. Finally, the simulations on the quadruple-tank process demonstrate the effectiveness of the proposed methods.