Optimal completely stealthy attacks against remote estimation in cyber-physical systems

This paper investigates the problem of designing the optimal completely stealthy attacks in cyber-physical systems. Different from the strictly stealthy attacks in the existing results which still have the possibilities to trigger the alarm and be invalid, a completely stealthy attack model is proposed such that the attack signals are able to bypass the detector successfully without being detected. Under the framework of the attacks, the remote estimation error is analyzed by deriving the recursion of the error covariance matrix, based on which the problem of attack design is transformed into a constrained optimization problem. By employing the Lagrange multiplier method, the optimal attack policy is derived which maximizes the remote estimation error and guarantees the complete stealthiness to the detector concurrently. Finally, simulation examples are provided to illustrate the effectiveness of this work. (C) 2022 Elsevier Inc. All rights reserved.