"Secret History is a highly recommended purchase to be considered by those with a serious interest in both the history and the ‘nuts and bolts’ of modem-day codes and ciphers. lt is both a work of pedagogy, along with its various exercises linked to individual chapters accessible via a linked website, and an interesting and exciting ‘read’ for anyone with a serious interest in the subject of today’s cryptology and its history."
—The Cryptogram, 2014
"The book presents a wonderful story of the development of this field. It is written more like a novel than like your traditional textbook, but it contains all the necessary material to also serve as a textbook. In fact, the author has created a companion website that provides sample syllabi and problems if the book is to be used in the classroom. … This book is enjoyable. I would recommend it to anyone interested in learning more about the topic of cryptology. It is especially interesting to someone like me, an algebraist who uses cryptology as a meaningful response to why topics in pure mathematics that do not seem to have obvious applications are still very important to study."
—MAA Reviews, August 2014
"Every once and a while a book appears that has a significant impact on the field of cryptologic history. David Kahn’s The Codebreakers and F.L. Bauer’s Decrypted Secrets are two such books. Secret History now joins that collection. … Secret History could be used as a textbook for a general education class that explores the history of cryptology (and ignores many of the mathematical sections) or for an upper-division class for mathematics or computer science majors that follows the historical evolution of cryptology (and pays attention to the mathematical sections). … What would appeal to a general audience is the engaging writing that reflects Bauer’s interest in and enthusiasm for all aspects of cryptology. … Bauer has merged cryptologic history with the mathematical foundations of cryptology in a correct, understandable, and enthusiastic presentation. Secret History is an excellent choice for a historian of cryptology, a teacher of cryptology, or anyone who wants to get a glimpse of cryptology."
—Chris Christensen, Cryptologia
"… one of the most engaging storytelling adventures on the evolution of secret keeping. In the first part of the book, Bauer (York College of Pennsylvania; formerly, scholar-in-residence, National Security Agency) discusses the inception of secret codes in Viking messages and substitution ciphers in the era of Caesar, as well as cryptography in works of fiction such as Edgar Allen Poe’s short story "The Gold Bug." Of course, Bauer also covers the famous Bletchley Park and its enigmatic star, Alan Turing. The second part focuses on current uses of cryptography and ends with a discussion of quantum cryptography. The book will challenge anyone with even a passing interest in cryptography to try to resist developing an intense passion for it. The math behind the systems described, while present, is never obscured by the fascinating setting in which it was developed. This is the way in which cryptography, one of the most difficult applications of discrete mathematics, was meant to be learned, with real-life cloak-and-dagger intrigue. Summing Up: Highly recommended. All levels/libraries."
—T.D. Richardson, CHOICE, Vol. 51, 2013
"… looking at the table of contents it appears EXCELLENT. The field is covered thoroughly and comprehensively and in a very up-to-date manner. It is by far the clearest and most comprehensive of the books dealing with the new cryptology, including of course the classic ciphers and some of the important historical ones such as Enigma and Purple, but also the newer systems such as DES and public-key cryptography. The history seems accurate and the book provides what I was unable to give cryptology—a mathematical underpinning to it all. … All of us in the cryptology community are grateful to you for it."
—David Kahn, historian, and author of The Codebreakers
"There have been plenty of 'light reading' books covering the history and mechanics of cryptology - this isn't one of them. Most focus on light math concepts and/or history - this isn't one of them. Instead, it covers both but provides much more depth and detail, surveying the political side of cryptology's developments, the use of codes in crime, music and literature, and considering how classical cryptology grew from Greek to modern times. It provides close examination of the groundbreaking works of cryptologists and considers specific algorithms and their functions, and it provides charts, graphs and calculations to show exactly how cryptology works. Any with more than a casual interest in the topic will find this a solid reference."
—California Bookwatch, January 2014