Finite-Horizon Strictly Stealthy Deterministic Attacks on Cyber-Physical Systems

This letter studies the properties and optimization of strictly stealthy attacks that cannot be detected by output and innovation-based detectors on cyber-physical systems. These attacks may target both the actuator and sensor communication channels with the goal of impairing the system's performance. We provide a necessary and sufficient condition for a system to be susceptible to a strictly stealthy attack of any given length. Furthermore, we analytically derive the optimal attack out of all possible strictly stealthy attacks with a particular length based on an energy constraint and a summation-based quadratic objective function. A numerical example is used to illustrate the theoretical results.