Security Evaluation of Cyber-Physical Systems by Modeling Attacks against Control Loops

Cyber-physical systems (CPSs) are deeply intertwining and integrating the physical processes with cyber components. In these intelligent systems, a process is monitored and controlled by cyber systems and different types of sensitive information is exchanged in a real-time manner. Nowadays, the security of these systems has been considered increasingly. Connecting physical devices to the cyber network makes the critical infrastructures more vulnerable to the adversarial activities. The primary target of attacks against CPSs is often disrupting physical processes under control. Since, improving the security of CPSs has gained considerable importance nowadays. This paper presents a method for modeling the security of CPSs using stochastic Petri nets (SPNs). The proposed method models the system control loop associated with anomaly detection systems (ADSs) in normal behavior and under security attacks. By using this model, we can investigate the consequences of the integrity and denial of service attacks against CPSs and perform probabilistic and temporal analysis of the system under security attacks. By solving the proposed model, the security of CPSs is estimated in terms of metrics, such as mean-time-to-failure and availability. Finally, the security of a chemical plant is investigated as an illustrative example to represent the effectiveness of the proposed modeling method.

کلیدواژه ها:

Cyber-physical systems (CPSs) ، security ، modeling ، quantitative evaluation ، stochastic Petri nets (SPNs)