A systematic guide to the technologies, standards, protocols, and means used for the transparent security of information interaction in computer networks, this resource enables an independent understanding of the various methods of providing computer and information security when using modern network technology. The basic features of both Web technologies and the distributed information processing technologies connected with them that are based on mobile programs are described, as are the network technologies that influence security. Also covered are the methods of attacking computer networks and practical guidelines for protecting a virtual network.