Integrating attack-defense graphs with online control to enhance cybersecurity of smart university campuses

A smart university campus (SUC) is a cyber-physical system that integrates advanced technologies, such as the Internet of Things, artificial intelligence, smart sensors, and cloud services, to improve educational, research, and administrative processes. The fusion of intelligent physical and cyber elements creates complex cybersecurity challenges for SUCs. This study proposes a fast and practical method for integrating an attack-defense graph approach with online control to enhance the cybersecurity of SUCs. The proposed approach involves three stages. First, the most vulnerable intrusion path in the attack graph, representing the shortest (minimum time) attack path in the SUC, is determined. In the second stage, countermeasures are applied to defend the most vulnerable assets. Finally, the third stage serves as a control layer that implements regular preventive and corrective control/monitoring measures to ensure the proper functioning and effectiveness of deployed defenses in the face of their unexpected failures and violations. The proposed polynomial method was tested and validated using the analysis of a real ransomware attack on Maastricht University in 2019, confirming its effectiveness and applicability.