Continuing a bestselling tradition, An Introduction to Cryptography, Second Edition features all of the requisite background material on number theory and algorithmic complexity, includes a historical look at the field, and offers updated and expanded exercise sets. In addition to updates throughout the text, this edition includes two new chapters on current and future applications that cover topics such as electronic mail, Internet security, protocol layers and SSL, firewalls, client-server model and cookies, network security, wireless security, smart cards, and biometrics. The book also provides additional information on cryptanalysis and primality testing as well as appendices on DES and primitive roots.