Beyond Anomaly Detection: Securing Critical Infrastructure Using Plantshield

Anomaly detectors are a useful tool for alerting a plant operator. However, such tools do not directly protect a plant from entering an undesirable state. In this paper, we focus on a system that goes beyond anomaly detection by preventing actuators from receiving commands that would otherwise move the plant to an undesirable state. The system, referred to as PlantShield, guaranties that even when the adversary gains access to plant controls, they cannot successfully send undesirable commands to the actuators. A version of PlantShield has been implemented and validated in an operational water treatment testbed.