Towards a common model for studying critical infrastructure interdependencies

The security of critical infrastructures, such as power systems, telecommunication networks, information facilities or even emergency and financial services, is a major aspect for our modern societies. One of the main threats is the growing interdependency between them. Failure in one infrastructure may cascade on others. In many infrastructures, it is mainly caused by the increasing complexity of operating constraints. In order to improve the overall security encompassing power and ICT and issue pertinent guidelines or regulations, it is first needed to better understand their interactions and interdependencies in an integrated view. Different tools are then needed: software able to simulate the dynamic or long term stability of coupled-infrastructures and benchmarks with coupled-components. A combined simulator (based on three dedicated software) and a test case were developed to identify the vulnerabilities of a power system caused by interdependencies with communication and information systems. The developed tool demonstrates the effects of failures from an infrastructure to others. To illustrate, the effects of a faulty router in the telecommunication network that cascade in the electrical infrastructure are presented.