ATTACK-RESILIENT CYBER-PHYSICAL SYSTEMS

Abstract

Cyber-Physical Systems (CPS) are ubiquitous systems that span digital, analog, and physical domains and range in both size and scope from a smart toaster to a complex nuclear power plant. CPS are becoming increasingly integral to everyday life, but this pervasiveness demands concern for malicious exploits and the exploration of potential unrealized utility. Attacks against systems that are part of our critical infrastructure are on the rise, especially against legacy systems that were deployed decades ago. This work presents a framework to allows CPS designers to augment existing or planned systems with low-cost sensors that measure emission from secondary processes to aid in the task of anomaly detection. Actuation limits are a method through which a hierarchical structured CPS can provide for dynamic preemptive mitigations against cyber-attacks. Additionally, alternative actuation paths that exist between coupled processes are uncovered and leveraged to be used in the event of component failure or compromise to regain some measure of control to keep the system in a safe operating region. A resilient CPS design will incorporate features from all three facets of detection, mitigation, and response to provide a layered defense against more capable cyber-attackers. This framework is demonstrated through a series of experiments performed in simulation and on hardware.