The Code Book

Ellen Knowlton Wilson brings us this review of a book which has succeeded in presenting one of the important concepts of modern life -- cryptography -- by grounding it in its historical roots as well as its modern applications, including ones not yet implemented. (Read more.)

The Code Book: the Evolution of Secrecy from Mary, Queen of Sco author Simon Singh pages 402 publisher Doubleday rating 8/10 reviewer Ellen Knowlton Wilson ISBN 0-385-49531-5 summary Singh chronicles the development of codes and ciphers as well as their roles in human events, and discusses the relevance of cryptography in the modern age.

In The Code Book: the Evolution of Secrecy from Mary, Queen of Scots to Quantum Cryptography, Simon Singh begins with the courtroom drama of the trial of Mary, Queen of Scots, and ends discussing current debate over the export of strong cryptography tools. In between, he touches on the identity of the Man in the Iron Mask, buried treasure, the Enigma machine, Navajo code-talkers and quantum money, in a manner accessible to laypeople.

Singh approaches the story of cryptography from the perspective of both scientist and science writer. He received his doctorate in physics from Cambridge and produced a documentary about Fermat's Last Theorem which aired on both the BBC and PBS. He is also the author of Fermat's Enigma, which tells the story of Fermat's Last Theorem. Singh's background has prepared him well for this subject; he has the scientist's eye for detail and the writer's ability to communicate concepts in a non-patronizing manner. "Turning to purists," he writes in the introduction, "I should apologise for the title of this book. The Code Book is about more than just codes... Ciphers play an integral role in cryptography, and so this book should really have been called The Code and Cipher Book. I have, however, forsaken accuracy for snappiness."

Indeed, this book is not intended for the diehard cryptography buff, but rather for the general reader. Should the reader become captivated by the subject, Singh has included a section of suggested further readings. The book also contains a contest for $15,000 -- The Cipher Challenge (http://www.4thestate.co.uk/cipherchallenge).

Singh states in his introduction that the objectives of this book as twofold: first, to chart the evolution of codes and chronicle their impact on history; and second, to demonstrate the importance of cryptography in the modern age. Singh clearly succeeds with his first objective, but I found the case for the second to be slightly weaker.

The types of codes and ciphers are illustrated with stories of historical intrigue, such as the treason trial of Mary, Queen of Scots, who was executed when the cipher alphabet and code words used by her co-conspirators was cracked, revealing her involvement in a plot unfamiliar to most modern readers. The development of frequency analysis and polyalphabetic substitution ciphers is interwoven with the story of the buried treasure in the American west. The mechanization of codes and ciphers is covered in the sections about the first and second World Wars, and the relation of language and cryptography is illustrated by the use of Navajo code-talkers during the Pacific campaign of World War II. Concepts of cryptography are presented in an accessible and enjoyable manner throughout the book, although readers already familiar with the subject may not gain any new knowledge.

The final three chapters of the book cover public-key encryption and quantum cryptography. I found the explanation of the concepts behind PGP to be clear, and was fascinated by the brief explanation of the legal struggles surrounding encryption. Singh makes some good points about the importance of privacy in the current age, but does not delve too far into the subject. Admittedly, the question of information ownership is such a large one that it merits its own book. The final chapter covers quantum cryptography, which is illustrated by the idea of quantum money. Quantum money would contain polarized photons, known only to the bank, rendering counterfeiting impossible. While still purely theoretical, the idea is fascinating, and indicates the changes sure to evolve as technology changes.

Summary:

The Code Book is an enjoyable and readable introduction to codes and ciphers for the layperson. Examples of the principles of cryptography are illustrated with examples from history, showcasing their importance of the history, and Singh attempts to make the case for the increasing importance of privacy as technology develops.

Purchase this book at ThinkGeek.

Table of contents:

• Introduction
  1. The Cipher of Mary Queen of Scots
  2. Le Chiffre Indchiffrable
  3. The Mechanism of Secrecy
  4. Cracking the Enigma
  5. The Language Barrier
  6. Alice and Bob Go Public
  7. Pretty Good Privacy
  8. A Quantum Leap into the Future
• The Cipher Challenge
• Appendices
• Glossary
• Acknowledgements
• Further Reading
• Picture Credits
• Index

Comments

Re:question and a half: (print books ok to export)

[mkettler]

Printed books generally do not have a problem with export from the US, finding protection under freedom of the press.

It is only digital media that has had a problem, since the argument is that source code on disk is a tool, not an expressive essay. Apparently the assumption is that OCR software doesn't exist outside the US either :)

Hence Applied Cryptography with detailed descriptions of strong algorithms can be exported by US booksellers, since there is no companion CD with it. The CD is sold only directly from the author (in MN), and only to US and Canadian buyers with check or money order drawn from a US bank. The CD is restricted from export, but the book is not. See http://www.counterpane.com/scode.html for more detail.

It is a strange country we live in where what format a book is in has great impact on where you can sell it.

One of the first binary systems

[ch-chuck]

an oldish article in Scientific American mentioned that a code Bacon used was one of the first uses of a binary numbering system -- it involved encoding a message using two slightly different fonts, distinguishable to those in the know, hidden in a open text letter. Every 5 characters in the open text would be one of two fonts (a or b, say), like "aabab (5-e) baaba (18-r) " etc.

Beefs w/the book (was Re:Friggin Netscape)

[xyzzy]

I thought that the digression into the breaking of Linear B was a fascinating comparison to the efforts of codebreakers. The point that he made was that the techniques are >remarkably the same -- a code is like a language (in the information theory/machine automata sense), and in this case you need to use BOTH mathematics AND a knowledge of the people communicating to successfully break the code. I actually went out and bought "The Decipherment of Linear B" by John Chadwick after reading "The Code Book". When I read it, maybe I'll post a review to Slashdot!

I do agree with your point about the "unbreakable" nature of Quantum Crypto. If there is any historical lesson to be learned here, it's that cryptography is a neverending arms race between the maker and the breaker. It just gets more interesting and has higher stakes as it goes on!

Second Slashdot review...

[AndyRae]

You can find the first review of this book here:

http://slashdot.org/books/99/10/07/1121201.shtml

andy

Re:One of the important concepts of modern life?

[Mr. Slippery]

Yeah, but cryptography is *nothing like* as important as these things.

I must disagree. To start with, cryptography is the rock upon which our banking and currency systems rest. If you use an ATM, or get your paychecks directly deposited, you've directly relied on cryptography. Even you keep your money in a mattress, the whole reserve banking system (upon which, for good or ill, the economy is based) needs it to function. Every day between one and two trillion dollars worth of interbank transfers are processed by Fedwire and the Clearing House Interbank Payment System; all these transations use cryptography.

And cryptography is essential for modern military operations. Whether you're a hawk or a dove, you can't help but admit that military operation have an important impact on the lives of people around the globe, and that impact would (for good or ill) be much lessened in the absence of secure communication. Cryptography is also important in the diplomacy that holds tensions short of a state of war - the old "Red Telephone" line between Moscow and Washington was protected with, IIRC, a one time pad.

Cryptography is used by people around the globe working for human rights; groups like Human Rights Watch and Amnesty International use cryptography to secure their communication.

So, if you want to engage in commerce, protect or attack a nation, or are concerned about human rights, cryptography is fundamental. There are good reasons why it gives certain government agencies extreme heartburn to think of cryptography in the hands of the rest of us...

Re:One of the important concepts of modern life?

[Mr. Slippery]

How can you say that when even now I'm sure that more than 90% of of the "modern world" has no inclination of what Cryptograhy is?

More than 90% of the "modern world" has no knowledge or understanding of the Otto cycle, Maxwell's equations, or the Von Neumann architecture, either. Yet they keep relying on cars, radios, and computers on an everyday basis.

The contest...

[Rocky]

I don't mean to bitch, but this review is a bit late for anyone who wasn't aware of the book and wanted to participate in the contest.

According to the leader board, 8 out of 10 of the codes have already been broken, so get going if you wanted to participate in the last two!

On an unrelated note, was anybody able to break the code on http://www.eruditorum.org ?
It has been taken down.

An excellent book on the subject!

[revision1_1]

I've read Kahn's _Codebreakers_ and Schneier's _Applied Cryptography_ and thought I'd pretty much covered the popular offerings on the subject, but picked up Singh's book based on an NPR interview I heard with him.

It was great. I even got my (non-crypto-geek) wife to read it, and she thoroughly enjoyed it. It's a little lighter on theory, but richer in descriptive narrative. If you've read Kahn, you'll find many of the same episodes related in The Code Book, but Singh does a better job of describing some of the historical contexts (specifically, the activities of Queen Elizabeth and Sir Francis Walsingham).

I was also glad to read some decent coverage of the much-under-appreciated Navajo Code Talkers of WWII, which barely rates a paragraph in Kahn. (By the way, The History Channel just ran an entire hour on the Code Talkers on their "Histories Mysteries" series - highly recommended)

I liked The Code Book so much, I went back and picked up his earlier book, _Fermat's Enigma_ and was enthralled by the 350 year quest to solve the Theorem.

Buy and enjoy. It deserves a place on the bookshelf next to Kahn and Schneier.

JQ

question and a half:

[LocalYokel]

Did this book have to be written overseas and imported to the U.S, or is it simply illegal to export this book outside the U.S.?

--

Why?

[zpengo]

Why is cryptography such an important subject? It seems to me that it's one of those "It's the principle of the thing!" ideas. What is the average geek actually doing with this powerful cryptography that we're all fighting for, except writing mash notes to his girlfriend, downloading video game demos, and buying penguin mints from ThinkGeek?

Online transactions can be encrypted all day long, and still be compromised by some 1337 srk1p7 k1dd13 who makes his way into a poorly secured database server. We need more awareness of the perils of e-commerce (on the side of those offering it), rather than stronger cryptography. Demand more secure online stores, not codes that take h@x0rz an extra day to crack.

(If you disagree, reply instead of modding me down).

Re:Friggin Netscape crashed on me the 1st attempt

[pldms]

The point about quantum cypto being unbreakable is this: current (non-quant) methods are falible because of their very nature. Large-number factoring, for example, is tedious, with no shortcuts (unless the film 'Sneakers' is correct ;-). But that's just a pragmatic issue. In principle it could be cracked (given a few millenia).

Quantum crypto, on the other hand, uses nature itself to help privacy. Listening in on my PGP email is simply impractical (and would be very dull - believe me). But to listen in on a quantum conversation without being detected would require breaking physical laws.

The worry, of course, is that quantum mechanics isn't the whole truth. But that is another story.

Allright...

[aTRaTiCa]

I took this book out of the Penn State Library a week or so ago. I didn't really get into it much however. The first two chapters were very boring in my opinion...The Mechanism of Secrecy and Cracking the Enigma were some of the more interesting things I remember skimming through.

I think a very strong interest in crypto is neccessary to really enjoy this book... I'm not big into crypto but I do think it's an intersting subject.

Anyone interested in crypto I'd say buy or borrow this book and give it a try yourself. It's not bad...

Friggin Netscape crashed on me the 1st attempt

[dmccarty]

Having just finished this book two weeks ago (I couldn't put the thing down, honest), this is a wonderful book that explores codes not necessarily from a codes and codebreaking standpoint, but from a historical perspective. Singh weaves a compelling narrative about why codes and codebreaking were important, and outlines the leapfrog game that codemakers and codebreakers have played for the last eight hundred years or so.

IMHO Singh really does a fascinating job of writing this book. There are only two downsides to this otherwise-excellent book:

• A digressive chapter on the "breaking" of the heiroglyphics and Minoan Linear B; interesting, but didn't have much to do with codes.
• After spending the entire book showing how every "unbreakable" code was broken, Singh gets way too excited about the coming "unbreakable" code, Quantum Cryptography. Granted, it certainly seems secure, but it seems strange to me that he would herald this method as unbreakable when there barely exists a means of transmitting it in the first place.

Other than these two minor points, I would seriously recommend this book. Also, the book delves extensively into the workings of the Nazi Enigma machine, which is also featured in the upcoming movie U-571.

--

Publications are exempt

[Dhericean]

Funnily enough the law that makes it illegal to export encryption hardware/software explicitly exempts publications (books, magazines, and academic papers) from the restriction.

This led to the strange operation by which the international version of PGP used to be created. The current US version's code listing was printed out on paper and this was legally exported. It was then OCRed back into electronic form and then manually examined to correct any OCR mistakes. This could then be compiled to create the non-US version.

Only in Printed Form

[Dhericean]

Source code in electronic form (on disk etc.) is not exempt which is the reason that PGP had to go through the process of printing it, exporting it, and OCRing it.

This is why Applied Cryptography's source CD is not shipped with the book as it would be illegal to export the CD without a license (but not the book containing the same information printed out).