Increased reliance on the Internet and other networked systems raise the risks of cyber attacks that could harm our nation's cyber infrastructure. The cyber infrastructure encompasses a number of sectors including the nation's mass transit and other transportation systems, banking and financial systems, factories, energy systems and the electric power grid, and telecommunications, which increasingly rely on a complex array of computer networks, including the public Internet. However, many of these systems and networks were not built and designed with security in mind. Therefore, our cyber infrastructure contains many holes, risks, and vulnerabilities that may enable an attacker to cause damage or disrupt cyber infrastructure operations. Threats to cyber infrastructure safety and security come from hackers, terrorists, criminal groups, and sophisticated organized crime groups, even nation-states and foreign intelligence services conduct cyber warfare.