The perceived need for computer and communications privacy has brought cryptology out of the shadow world of espionage and secrecy with which it has been traditionally associated. The advent of the micro, the PC and the inexpensive modem make the cryptographic option a concern of everyday users as well as of the mainframe or mini installation. More and more cryptographic products are likely to come on stream in the near future, and this book provides the foundations for appreciating them. There are few works which introduce the subject to the general reader, a lack which this book makes good. It surveys the chief cryptographic algorithms that have been developed over the centuries. Not intended as a manual of cryptology, the book is essentially an introduction for those who know little about the subject but would like to know more, particularly concerning the latest public key cryptosystems and IBM's Data Encryption Standard. Professional users of microcomputers, whether in the business or personal areas, may find the book valuable reading, as will computing students, and those with an interest in cryptology in general.