Continuity in critical network infrastructures: Accounting for nodal disruptions

Since the attacks of September 11 2001, there has been a renewed interest in identifying, protecting and maintaining the functionality of critical infrastructure systems in the United States and abroad. However, because these systems are relatively complex, many difficulties have emerged when attempting to differentiate between elements of the infrastructure that are “critical” and those that are not. In an effort to resolve this issue, the U.S. government has released several important reports detailing the specific infrastructures and assets considered critical to national security, governance, public health, and the economy (White House 2003). Table 10.1 displays the key sectors and assets outlined in the National Strategy for the Physical Protection of Critical Infrastructures and Key Assets (Strategy).