Review: The Code Book – the most entertaining book on cryptography you’ll ever read

I recently wandered into a thrift store and as is usual in these stores I headed to the book section.(I live by the maxim that you can never own too many books.) The only thing that really caught my eye was a hardcover edition of The Code Book: The Science of Secrecy from Ancient Egypt to Quantum Cryptography by Simon Singh. A quick perusal indicated it would be worth the shelf space.

However, I severely underestimated how much I would enjoy this book. I’m about half way through and find it so interesting and compelling a read that I feel I have to write about it.

The thing that really strikes me about this book is how entertaining and readable it is. I am not a big crypto or security guru, so I came to this book largely ignorant of of the topics and history.

The book is a wonderful blend of how encryption works with the history that surrounded its development. For such a seemingly-complex topic, Singh seems to have hit the perfect blend of history and instruction. Starting with the rudimentary Caesarian ciphers (basically, letter substitution) he builds up the techniques in the millenia-old one-upsmanship game between those who encipher and those who attempt to decipher. He starts with frequency analysis and history progresses he builds upon the previous techniques in explaining ever-more sophisticated attacks.

Surrounding this technical (yet still easy to understand) instruction is a fairly thorough narration of the history where these ciphers played a crucial role, from ancient Egypt, Julius Caesar, Mary Queen of Scots’ plot against Queen Elizabeth I, to legends of buried treasure protected by unbreakable ciphers, to the formidable German Enigma machine–

And let me be clear—he will teach you exactly how Enigma worked! It’s not that complicated, once you understand the principles that came before it.

Similarly, he explains how first the Polish and then the British cracked the Enigma as it evolved from the 1930’s to the end of the war, the mistakes the Germans made, and the things that, for example, the German Navy did to increase the security of it so that it became essentially unbreakable without external help (i.e., finding a codebook).

He discusses the Navajo code talkers (there is more to it than simply speaking an obscure language!), public key security, and finally quantum computing.

If you enjoy computer security topics, history, or just like to geek out, this is a great book to read.

Coincidentally, Simon Singh is also at the center of an unfortunate controversy in the UK surrounding some (I believe justified) comments he made about the British Chiropractic Association’s practices of encouraging procedures that could be considered unsafe. Rather than defend the practices with facts, they have decided to sue him for libel (the UK is infamous for having draconian libel laws that strongly favor accusers). You can learn more at his website.

You can also read a thorough explanation of the events at the Bad Astronomy blog.