Interdependencies between Critical Infrastructures: Analyzing the Risk of Cascading Effects

One of the most challenging problems, when protecting critical infrastructures, is the identification and assessment of interdependencies. In this paper we examine the possible cumulative effects of a single security incident on multiple infrastructures. Our method provides a way to identify threats that may appear insignificant when examining only first-order dependencies, but may have potentially significant impact if one adopts a more macroscopic view and assesses multi-order dependencies. Based on previous work, we utilize existing first-order dependency graphs, in order to assess the effect of a disruption to consequent infrastructures.