The Internet, as well as other telecommunication networks and information systems, have become an integrated part of our daily lives, and our dependency upon their underlying infrastructure is ever-increasing. Unfortunately, as our dependency has grown, so have hostile attacks on the cyber infrastructure by network predators. The lack of security as a core element in the initial design of these information systems has made common desktop software, infrastructure services, and information networks increasingly vulnerable to continuous and innovative breakers of security. Worms, viruses, and spam are examples of attacks that cost the global economy billions of dollars in lost productivity. Sophisticated distributed denial of service (DDoS) attacks that use thousands of web robots (bots) on the Internet and telecommunications networks are on the rise. The ramifications of these attacks are clear: the potential for a devastating, large-scale network failure, service interruption, or the total unavailability of service. This book provides an integrated view and a comprehensive framework of the various issues relating to cyber infrastructure protection. It covers not only strategy and policy issues, but also the social, legal, and technical aspects of cyber security as well.