This important text/reference presents a comprehensive guide to the field of computing and information security and assurance. The book takes a broad view of computer network security, encompassing online social networks, and wireless and mobile systems. This fully updated new edition explores the security issues, vulnerabilities and dangers encountered by the users of modern computing and communication devices, highlighting the need to develop improved algorithms, protocols, and best practices to enhance the security of public, private and enterprise systems alike. Topics and features: introduces the fundamentals of traditional computer networks, the security threats they face, and the best practices currently in use; discusses the security challenges introduced by virtualization software, cloud computing and mobile systems; examines the security quagmire presented by the home computing environment and the growing number of home hotspots (NEW) ; raises important legislative, legal, social, technical and ethical security issues, including the tension between the needs of individual privacy and collective security; provides both quickly workable and more thought-provoking exercises at the end of each chapter, with one chapter devoted entirely to lab exercises; supplies additional support material for instructors at an associated website, including laboratory exercises and projects, answers to selected exercises, and course slides. This unique work is suitable as both a teaching and a reference tool for all those interested in learning about security in the evolving computing ecosystem. Computer network and data security personnel and policy makers will also find the guide to be a useful and unique source of ideas.