An early example is a Roman work, now lost, and known only by references to it. Later, various authors wrote (variously responsibly) on cryptography *** give examples ***, much of which was more mystical and reputation promoting than worthwhile. In the 19th century, the general standard improved somewhat (eg, Kerchoff and Kasiski) and with Hill and Friedman in the early 20th century, some cryptography books lost the mystical tone. Others, also not very mystical, were simply classified. However, with the mechanization of armies and the invention of radio, communications (especially military communications) went wireless and some means of protecting messages which could necessarily be heard by all became imperative.

Thus after WWI, cryptography became not merely a useful grace note, but important. Thereupon, publicly available material started to diverge from actual cryptographic, and cryptanalytic, practice, largely by leaving out things. There began a period in which public descriptions of cryptography were either intended for children, deliberately misleading, or limited to historical issues. Some, such as Herbert Yardley's The American Black Chamber were mixtures of everything, including a return to the personal reputation puffery of the Renaissance.

Until the late twentieth century most aspects of modern cryptography were regarded as the special concern of governments and the military, and were protected by custom and in some cases by statute. The most significant work to be published on cryptography in this period is undoubtedly David Kahn's The Codebreakers, which was published at a time (mid 60s) when virtually no information on modern cryptography was available. Kahn claimed that over ninety percent of its content was previously unpublished. The book caused serious concern at the NSA despite its lack of coverage of specific modern cryptographic practice, so much so that after failing to prevent the book being published they informed NSA staff not to even acknowledge the existence of the book. In the US military, possession of a copy by crypto personnel was grounds for some considerable suspicion. Perhaps the greatest importance of the book was the impact it had on the next generation of cryptographers.

Significant books on cryptography include:

Table of contents

1 Cryptographic techniques 2 History of cryptography 3 Overview of cryptography

Cryptographic techniques

• Ferguson, Niels, and Schneier, Bruce - Practical Cryptography, Wiley, 2003, ISBN 0471223573. Up to date cryptography reference. Covers both algorithms and protocols. This is an in depth consideration of one cryptographic problem, including paths not taken and some reasons why. Most of the material is not otherwise available in a single source. Some is not otherwise available. In a sense, a follow-up to 'Applied Cryptography'.
• Schneier, Bruce - Applied Cryptography, 2 ed, Wiley, ISBN 0471117099. The best single volume available covering modern cryptographic practice and possibilities. About as comprehensive as a single volume could have been. Well written, not overly mathematical, and so accessible -- mostly -- to the non-technical.
• Schneier, Bruce - Secrets and Lies, Wiley, ISBN 0471253111, a discussion of the context within which cryptography and cryptosystems work. Meta-cryptography, if you will. Required reading for would-be cryptographers, and nearly so for all cryptography users.
• Ross Anderson -- Security Engineering, Wiley, advanced coverage of computer security issues, including cryptography, by one of its foremost practicioners, and most likely its best writer. Covers much more than merely cryptography. Brief on most topics due to the breadth of coverage. Exceptionally clearly written.
• A. J. Menezes, P. C. van Oorschot and S. A. Vanstone - Handbook of Applied Cryptography ISBN 0849385237 (online version). Equivalent to Applied Cryptography in many ways, but heavily mathematical. For the technically inclined. Covers few meta-cryptographic topics, such as crypto system design. This is regarded as the standard reference work in cryptography.
• Nigel Smart - Cryptography: An introduction. Again similar to Applied Cryptography, but covers more modern material and is aimed at undergraduates covering topics such as number theory and group theory not generally covered in cryptography books.
• Douglas Stinson - Cryptography: Theory and Practice a work somewhere between HAC and Applied Cryptography in terms of mathematical details. Covers topics in a textbook style but with more matematical detail then normal.
• Oded Goldreich's Foundations of Cryptography series [1] provides a comprehensive formal treatment of the theory underlying modern cryptography. The focus is on mathematical abstractions, rigorous constructions and proof techniques; practical aspects are best sought elsewhere. Requires computer science background.
  • Goldreich, Oded (2001). Foundations of Cryptography: Volume 1, Basic Tools. Cambridge University Press. ISBN 0-521-79172-3 (fragments available at the author's web site). Discusses the basic constructs: one way functions, pseudorandomness and zero-knowledge proofs.
  • Goldreich, Oded (2004). Foundations of Cryptography: Volume 2, Basic Applications. Cambridge University Press. ISBN 0-521-83084-2 (drafts available at the author's web site). Using the tools developed in vol. 1, discusses encryption, digital signatures and cryptographic protocols.

• Bamford, James - The Puzzle Palace : A Report on America's Most Secret Agency ISBN 0140067485, and the more recent Body of Secrets. The best of a quite small group of books about the US Government's NSA. Most are inadequate, and untrustworthy, for various reasons, including an active reluctance to permit accurate information to be released in any form.
• Kahn, David - The Codebreakers ISBN 0684831309 The best available single volume source for cryptographic history, at least for events up to the mid '60s (ie, to just before DES and the public release of asymmetric key cryptography). The added chapter on more recent developments (in the most recent edition) is regrettably far too thin. See also his other publications on cryptography, and cryptographic history, which have been uniformly excellent.
• Singh, Simon - The Code Book ISBN 1857028899. An anecdotal introduction to the history of cryptography, but much better than such an approach might be expected to produce. Covers more recent material than does Kahn's The Codebreakers. Well written. Sadly, the included cryptanalytic contest has been won and the prize awarded; the cyphers are still worth having a go at, however.