Covert Misappropriation of Networked Control Systems: Presenting a Feedback Structure

The increasing availability of Internet connectivity and networked actuation and sensing components has supported the growth in control systems operated over public networks. Controllers and plants no longer need to be physically colocated as measurements and actuation signals can be sent digitally. Supervisory systems can monitor and control geographically widespread components. However, such systems are now exposed to the risk of remote interference. A feedback structure that allows an attacker to take over control of the plant while remaining hidden from the control and supervisory system(s) is presented. The objective is not to facilitate such attacks but rather to make clear the degree to which the takeover of plant control can be hidden when a sophisticated attacker has some plant knowledge and signal intervention capabilities.