Optimal Stealthy Attack on Cyber-Physical Systems and Its Application to a Networked PMSM System

This article investigates the stealthy attack on cyber-physical systems under the stochastic communication protocol (SCP), which is used to avoid data collisions. The attack stealthiness is characterized by the Kullback–Leibler divergence and the attack performance is measured by the corrupted error covariance. This article aims to maximize the attack performance for a certain stealthy level. Different from the existing results, our proposed attack strategy takes the SCP-introduced effects into account and exploits incomplete measurement outputs at each time instant to construct an attack model. Then, a nonconvex optimization problem is formulated to achieve the desired attack performance for a given stealthy level. By applying the monotonic optimization technique, the nonconvex problem is converted to two optimization problems with equality constraints. Then, the analytical expressions of the attack parameters are derived. Finally, simulations on a three-tank system and experiments on a networked permanent magnet synchronous machine prototype system are conducted to validate our proposed theoretical results.