The following review of APPLIED CRYPTOGRAPHY appeared in the January 1994 issue of Cryptologia (v. 18, n. 1). Written by Louis Kruh. The past twenty years have seen an explosive growth in public research into cryptology, accompanied by an unprecedented public awareness of matters cryptologic. Programmers and engineers trying to benefit from the fruits of this research, to solve real-world problems, have often been stymied by not knowing where to start looking, let alone when to stop. This book is for them. Written as a "comprehensive reference work for modern cryptology" the book succeeds both as an encyclopedia survey of the past twenty hears of public research and as a hansom "how-to" cookbook of the state-of-the-art. It could well have been subtitled "The Joy of Encrypting." The author's style is colloquial and informal, but never imprecise. Theory takes a back seat to clarity and directness, without deliberate misrepresentation; unabashed informed opinion wins out over academic hesitations. Since the work is a practical snapshot of the field, circa mid-to- late 1993, several of the book's recommendations may prove timely: new results seem to be reported monthly. While his political axe is never concealed the book is written as a whetstone for others rather than a soapbox rant, and the focus is manifestly practical solutions and the tools with which to achieve them. After a forward from Whitfield Diffie the author explains foundations; examined protocols; discusses techniques; presents algorithms; explores the real world (including legal and political aspects); and finishes up by printing read-to-run C source code programs of several of the algorithms, including ENIGMA, DES and IDEA. Reflecting the confused nature of the real world, a set of IBM PC disks containing the sources published in the book is available from the author--but only to residents of the USA and Canada. Drawing on 908 references and the collected experience of contributors throughout the Internet and around the world, this book will be a useful addition to the library of any active or wouldbe security practitioner. It's the first review of the book that has appeared in print, and I am very pleased with it. The book has turned out to fill two very different niches. One, it is the book that people are being handed to read when they want to learn about the field. Two, it is the reference work that people are turning to first if they want to find out about some aspect of cryptography. The third important niche, which the book does not fill, is that of a textbook. This field sorely needs a textbook. Anyone interested? Bruce