Cryptography is a key technology in electronic key systems. It is used
to keep data secret, digitally sign documents, access control, and so
forth. Users therefore should not only know how its techniques work, but
they must also be able to estimate their efficiency and security. Based
on courses taught by the author, this book explains the basic methods of
modern cryptography. It is written for readers with only basic
mathematical knowledge who are interested in modern cryptographic
algorithms and their mathematical foundation. Several exercises are
included following each chapter. This revised and extended edition
includes new material on the AES encryption algorithm, the SHA-1 Hash
algorithm, on secret sharing, as well as updates in the chapters on
factoring and discrete logarithms.