Decrypted Secrets

Rating:
Summary: Excellent Modern Textbook
Review: I read this book in the original German (even though reading in German is still a labor for me), and the effort was amply rewarded. This book is a first course in cryptography, at the upper undergraduate or beginning graduate level. Its competition would be books like Denning's or Beker and Piper or Koblitz' series. Denning's book is still great and worth buying (and Ms. Denning is a wonderful, accomplished, and intelligent person), but Bauer is more modern and complete. Koblitz' books are all first rate, but Bauer stays on the task of cryptology much more exactly and usefully. This is the basis of an excellent course in several German universities, especially in Munich. If I taught another course purely on cryptography (and not as part of a larger math curriculum---where Koblitz' book is best), I would certainly use this as the text. However, even though this is best, I really think everyone should still buy, read, and treasure Ms. Denning's book, Cryptology, too. (A true classic is never actually superseded.) Buy Bauer. It is better than an existing classic. While I don't have the English version yet, and cannot, therefore, vouch for the quality of the translation, I think that Springer Verlag is such a reliable editor that we can both trust that the translation will be good before we even see it.

Rating:
Summary: Truly Neat Book!
Review: This book makes a good technical companion to Kahn's historic treatment in 'The Code Breakers'. It covers the technology up through the advent of computers. Its treatment is technical, going into details about how an encryption technique is performed, and how it is attacked. This book is the first place where I've seen the Enigma machine described in enough detail to understand how it works (or they worked since there were many variations and many of them are discussed here), and how to actually build (or simulate) one. It's a big book, and I carried it around for months, sometimes just diving into a chapter or topic. I loved it.

Rating:
Summary: Superb!
Review: This is an amazing book, and relatively inexpensive; Springer-Verlag has done it again.

Rather than being a dry recitation of encryption and cryptanalysis schemes, Bauer provides a great deal of information about what actually goes wrong when one tries to construct a cipher that must be used under pressure by non-cryptologists, with plenty of historical examples to illustrate his points. And he discusses at some length the ways in which cryptanalysts can hope to unravel ciphers and codes too strong to be broken by standard methods. Much of what he has to say I had never seen in print before; some of it was brand new to me. Perhaps it helps that Bauer is German, and doesn't have to write with the uneasy feeling that NSA or MI-6 is looking over his shoulder at every line he writes. For example, his explanation of how Robert Murphy compromised an American cipher in WW II so badly that the Germans could read it easily is one that I think some American officials would probably still prefer not to have in print.

Despite comments by other reviewers and by Cryptologia, I think it requires a certain mathematical sophistication to absorb much of the material in this book. The math is not hard, but Bauer implicitly assumes a mathematical mindset and a familiarity with the terminology of pure mathematics that most college undergraduates don't have. So I wouldn't choose it as the primary text for a first course in cryptology, but I would certainly use it as a supplementary text. I know of no other book that contains so much material on the practical realities of cryptology.