Modeling Security of Power Communication Systems Using Defense Graphs and Influence Diagrams

The purpose of this paper is to present a framework for assessing the security of wide-area networks (WANs) used to operate electrical power systems. The framework is based on the formalism influence diagrams and the concept of defense graphs and facilitates a so-called consequence-based analysis of the security problem. The framework is also capable of managing uncertainties, both related to the efficacy of countermeasures and the actual posture of the supervisory control and data-acquisition system. A model over WAN attacks and countermeasures and experiences from applying the framework are described.