Supervisory control and data acquisition (SCADA) networks contain computers and applications that perform key functions in providing essential services and commodities (e.g., electricity, natural gas, gasoline, water, waste treatment, transportation) to all Americans. As such, they are part of the nation’s critical infrastructure and require protection from a variety of threats that exist in cyber space today. By allowing the collection and analysis of data and control of equipment such as pumps and valves from remote locations, SCADA networks provide great efficiency and are widely used. However, they also present a security risk.