Petri-net based attack time analysis in the context of chemical process security

Chemical production- or storage facilities may have a strong appeal to terrorists due to their potential for causing great losses and possible huge societal impact. In view of the deficiency of attack trees, especially the impact of attacker numbers on the attack time, a timed colored Petri-net based attack process modeling approach, as well as a simulation based security failure probability analysis approach for security management, is proposed in this paper. The number of attackers has a key influence on the logic relationship of attack events. For performing the events represented by the logical gates (mainly AND gate and OR gate) of an attack tree, the influence of a different number of attackers on the attack time is discussed, and corresponding timed colored Petri-net based modeling approaches are provided. Comparing the duration of an attack process with an assumed interval of security inspection, a security failure probability can be obtained.