Cyber and physical infrastructure interdependencies.

The goal of the work discussed in this document is to understand the risk to the nation of cyber attacks on critical infrastructures. The large body of research results on cyber attacks against physical infrastructure vulnerabilities has not resulted in clear understanding of the cascading effects a cyber-caused disruption can have on critical national infrastructures and the ability of these affected infrastructures to deliver services. This document discusses current research and methodologies aimed at assessing the translation of a cyber-based effect into a physical disruption of infrastructure and thence into quantification of the economic consequences of the resultant disruption and damage. The document discusses the deficiencies of the existing methods in correlating cyber attacks with physical consequences. The document then outlines a research plan to correct those deficiencies. When completed, the research plan will result in a fully supported methodology to quantify the economic consequences of events that begin with cyber effects, cascade into other physical infrastructure impacts, and result in degradation of the critical infrastructure's ability to deliver services and products. This methodology enables quantification of the risks to national critical infrastructure of cyber threats. The work addresses the electric power sector as an example of how the methodology can be applied