A comprehensive yet comprehensible and witty guide to the latest advances in computer network security protocols. In this book the authors go beyond documenting standards and technology; they contrast competing schemes, explain weaknesses and strengths, and describe common mistakes people make when intending to design secure systems.* examines the state of computer network security - what works, what doesnt, and why. * explains clearly the cryptographic algorithms on which most network data systems depend. * provides comprehensive descriptions of many authentication systems, including Kerberos, NetWare, Lotus Notes, DASS, and KryptoKnight. * offers a rigorous treatment of secure electronic mail standards, including PEM, PGP, and X.400. * describes classic security pitfalls and how to avoid them when designing protocols.