Stealthy Local Covert Attacks on Cyber-Physical Systems

The networking of Cyber-Physical Systems (CPS) is a worldwide trend. With the growing accessibility of data, vulnerability to cyber attacks increases. If the cyber attack remains undetected by the monitoring system, it is called stealthy. Stealthiness of the attack produces the risk that an adversary can take control over a CPS via a communication network and remain unnoticed. We aim to call attention to this problem by proposing a new attack scenario called local covert attack. Different from the previously known covert attack introduced in (Smith, 2011), the local covert attack proposed here needs less disruption resources and does not require the access to all control input signals and sensor output signals. We show that the local covert attack can be made completely stealthy by applying the decoupling technique or by combining the basic idea of covert attack and zero-dynamics attack. Simulation results are provided to demonstrate the stealthiness of the proposed local covert attacks.