This comprehensive guide exposes the security risks and vulnerabilities of computer networks and networked devices, offering advice on developing improved algorithms and best practices for enhancing system security. Fully revised and updated, this new edition embraces a broader view of computer networks that encompasses agile mobile systems and social networks. Features: provides supporting material for lecturers and students, including an instructor manual, slides, solutions, and laboratory materials; includes both quick and more thought-provoking exercises at the end of each chapter; devotes an entire chapter to laboratory exercises; discusses flaws and vulnerabilities in computer network infrastructures and protocols; proposes practical and efficient solutions to security issues; explores the role of legislation, regulation, and law enforcement in maintaining computer and computer network security; examines the impact of developments in virtualization, cloud computing, and mobile systems.