Code Breaking

Code Breaking: A History and Exploration has joined Simon Singh's The Code Book on my bookshelf, and it's hard to read either of these books without comparing it to the other. If you've read the Singh book, though, you'll certainly find that the material covered overlaps heavily. Read on to find out if you'd enjoy checking out Kippenhahn's work.

Code Breaking: A History and Exploration author Rudolf Kippenhahn pages 283 publisher The Overlook Press rating 8.5 reviewer timothy ISBN 1-58567-089-8 summary A readable, lucid introduction to encryption with an emphasis on WWII applications, but with a range from Caesar to PGP.

The Big Picture Lucidly, and in the way of great teachers who neither baffle nor condescend, Kippenhahn tells the story of how encryption and cryptanalysis has evolved through the ages, and sprinkles examples and reader exercises throughout. Unlike Singh's book, though, which starts its historical wanderings with Mary, Queen of Scots, Kippenhahn's draws the largest chunk of its examples from World War II. Given the scope and innovation in encryption that occurred in WWII, this can hardly be seen as a limitation. In fairness, that's not to say that many of his examples don't come from other times before or since World War II. Some of the hard to overlook techniques of encryption, as well several of the famous coded messages on which some of the turns of modern history have hinged are represented here. For instance, the Zimmerman telegram, probably one the most-pivotal, least-talked-about-in-school transmissions of the century, draws several pages explaining how the American and British espionage services ended up cracking the message which could have led to war between Mexico and the U.S.

As the book progresses, examples from newer and older times (and contexts from literature to lovers' secret messages) are presented with enough panache to make you forget that this is a book about a topic which is often rendered dry as dust.

In taking this broad-sighted approach, Kippenhahn has opened his book to a wider audience than likely browse the computer-books section in the local Barnes & Noble.

Revisiting the two big wars of this century provides an excellent backdrop, but modern developments in secret writing are not neglected; the latter parts of the book include a description of several modern encryption schemes (usually using DES as the example), and a comprehensible explanation of public-key encryption.

Points to Consider Everything is not perfect, though: Kippenhahn, for example, does not touch on some of the newest developments in encryption and cryptanalysis. The book was first published in English only in 1998, though, and it's hard to fault him for not attempting to delve into the possibilities of quantum computers for either side of the secrecy game.

Interestingly, this work in a translation of a German text (Kippenhahn collaborated in Ewald Osers' translation), but as Kippenhahn points out in his introduction, it's more than a simple translation; the examples in many cases have been transformed from the original to work well with English words and frequency tables rather than German.

This book is definitely not aimed at experts who wish to pick up subtle points or learn the latest developments in encryption; instead, it's a historical overview which happens to teach the classic techniques of encryption and decryption through examples. If you want Applied Cryptography, buy that instead. (Or in addition -- no reason not to be well-rounded!)

The Upshot: Back to the inevitable comparison to The Code Book: If you've read Singh's book, and enjoyed it, you won't regret reading Code Breaking, but it might be wise to browse it before buying, to make sure that similarities won't leave you with too bad a sense of deja vu. If you've read neither one, Kippenhahn's work is no less stimulating.

1. Secret Writing in War and Peace
2. Hidden Messages and Codebooks
3. Codebooks in World War I
4. He Came, He Saw, He Encoded
5. How a Monalphabetic Code is Cracked
6. Caesars in Rank and File
7. Keywords Without End
8. Shuffled Texts
9. From Coding Disk To Enigma
10. Enigma's Secret is Revealed
11. The Arrival of the Computer
12. Encryption Quite Publicly
13. Smart Cards, One-way Functions, and Mousetraps

• Appendix A: A homemade encrypting machine
• Appendix B: Your computer as Enigma
• Appendix C: How the three magic keys are determined
• Appendix D: PGP, the encryption program from the Internet

You can purchase this book at ThinkGeek.