This book is a clear and informative introduction to cryptography and data protection--subjects of considerable social and political importance. It explains what algorithms do, how they are used, the risks associated with using them, and why governments should be concerned. Important areas are highlighted, such as Stream Ciphers, block ciphers, public key algorithms, digital signatures, and applications such as e-commerce. This book highlights the explosive impact of cryptography on modern society, with, for example, the evolution of the internet and the introduction of more sophisticated banking methods.

Fred Piper has been a Professor of Mathematics at the University of London since 1975 and has worked in security since 1979. In 1985 he formed a company, Codes & Ciphers Ltd., which offers consultancy advice in all aspects of information security.He has lectured worldwide on a wide range of topics in information security, both academically and comercially.

Sean Murphy is currently a Reader in the Information Security Group. His research interests centre on cryptology, especially encryption algorithms. He published some of the early papers on differential cryptanalysis, and has written papers on a variety of cryptographic algorithms such as DES, FEAL, IDEA, SAFER and Twofish.