Process-Aware Defenses for Cyber-Physical Systems

Doctoral thesis, 2021

The increasing connectivity is exposing safety-critical systems to cyberattacks that can cause real physical damage and jeopardize human lives. With billions of IoT devices added to the Internet every year, the cybersecurity landscape is drastically shifting from IT systems and networks to systems that comprise both cyber and physical components, commonly referred to as cyber-physical systems (CPS). The difficulty of applying classical IT security solutions in CPS environments has given rise to new security techniques known as process-aware defense mechanisms, which are designed to monitor and protect industrial processes supervised and controlled by cyber elements from sabotage attempts via cyberattacks. In this thesis, we critically examine the emerging CPS-driven cybersecurity landscape and investigate how process-aware defenses can contribute to the sustainability of highly connected cyber-physical systems by making them less susceptible to crippling cyberattacks. We introduce a novel data-driven model-free methodology for real-time monitoring of physical processes to detect and report suspicious behaviour before damage occurs. We show how our model-free approach is very lightweight, does not require detailed specifications, and is applicable in various CPS environments including IoT systems and networks. We further design, implement, evaluate, and deploy process-aware techniques, study their efficacy and applicability in real-world settings, and address their deployment challenges.