Network attacks and defense systems

In recent years there has been significant increase in attacks via wired, wireless and optical transmission platforms, such as DDoS, viruses, worms, spyware, and malware, etc, causing huge economical and social damage. While the network attack systems have become more easy-to-use, sophisticated, and powerful, interest has greatly increased in the field of building more effective, intelligent, and active defense systems which are distributed and networked. Today's network defense systems face significant challenges to provide protection to networks and hosts.