Cyberspace and physical systems are becoming more complex and inextricably linked to each other. As Information Technology (IT) becomes increasingly integrated with physical infrastructure operations, there is increased risk for wide scale or high-consequence events that could cause harm or disrupt services vital to the American economy. Some federal agencies spent more than half of their IT budget last year on resources to strengthen the security of their IT systems against cyber-attacks. However, a recent survey of agency directors across the government found that while 90 percent of respondents felt protecting their agencies from cyber-attacks was one of the top five most critical issues they face, only 33 percent indicated they have the resources necessary to adequately combat cyber-attacks against agency controlled physical infrastructure.