The Code Book: The Science of Secrecy from Ancient Egypt to Quantum Cryptography

This is a really excellent book. It is beautifully written, with numerous clear descriptions of tricky concepts. Best of all, it is peppered with first rate anecdotes and fascinating historical context.

Overall, it is a real page turner that I found hard to put down. I feel it is somewhat harsh to reduce from a five star review simply because as the book gets nearer to the present day, it feels more out of date.
It was published in 1999 and the sections on "modern" computing and developments are inevitably rather dated.

Nonetheless, the first 80% of the book is timeless and was a pleasure to read. I will definitely read his subsequent book before long.

On the surface of it, The Code Book is a very unglamorous book - a somewhat analytical book filled with technical jargon on the history of cryptography, starting from its first mentions in written record to the somewhat confusing introduction to quantum computing and quantum cryptography.
But on a deeper glance, Simon Singh reveals himself as a passionate and intense geek who wants to explain how our communication is encrypted and decrypted to laypeople, who might not know what algorithms and modulus functions are but who deserve to know what cryptography is. It is telling that most of the concepts he teaches are through stories - why a particular cypher was invented and how history could have been much different if a few specific show more messages were still secure. It was heartening to note that even knowing all the basics - there was a lot of stuff to absorb - including the inner workings of Enigma used in WW2, the decryption of Linear B, an extinct Mediterranean language.
The Code Book's ending chapters have dated horribly, though. Simon envisioned a future where the public would need cryptography because they would be emailing forms containing their credit card information to retailers for e-commerce. Amazon took this concept to a hitherto unforeseen level. Moore's Law has stagnated, the debate on cryptography has changed immensely, for better or worse - and quantum computing remains as nascent as ever. Still, the basics of cryptography have remained the same - for that alone; this is a fine read. show less

Coming on 20 years after the book was written, it’s still quite awesome despite all our subsequent advances in cryptography.

Or rather, I should say, we’re still living in the same world already transformed by pretty good encryption. The methods for breaking the security still falls in the same category as usual: interception. Of course, the means of interception has gotten amazingly good and creative as hell, but that isn’t the primary scope of this book.

Rather, it’s about an awesome crash course in the history of encryption from the Middle Ages or earlier, say Roman or Greek, all the way forward to mechanical solutions a-la Babbage and right into the thrilling good stuff of WW2, including Turing and the awesome Code Talkers. show more

The advances since then are almost stunningly fascinating, however, and aside from Zimmerman’s courageous advent of PGP, the REST of the story may well be trapped under National Security blankets still.

Alas. What I wouldn’t give to get a backstage pass to those goings-on. :)

Well written, accessible, and rather thorough, this book remains one of the best books on encryption for laypersons. Highly recommended. show less

Hiding secrets (i.e., cryptography or the science of encryption) has become an increasingly important topic in the modern Information Age. It’s not just the stuff of the military and diplomacy. We cannot communicate secrets like credit card numbers over the Internet without it. In this book, dated around the turn of the millennium, Singh shares the history of encrypting messages. He begins to forecast its impact in the twenty-first century while noting exciting trends in the directions of quantum computing and quantum cryptography.

Near the beginning of the Common Era, Julius Caesar famously used a “caesar cipher” to cloak his messages. Conceptually, it’s so easy to implement that my elementary-school-aged daughter learned about show more it. But soon, it became just as easy to break it. This war between code-makers and code-breakers has continued throughout history. Singh tells us of the major battles of this war in a lively and informative way. He provides both the historical setting and technical details behind these events.

Some of the most interesting stories surround the events of the twentieth century’s world wars. Singh tells each of these stories, with particular depth surrounding the British efforts. Alan Turing and others from England’s eclectic Bletchley Park are described in detail. Described in just as exciting of a manner are modern mathematical efforts around digital encryption. RSA and DES encryption are meticulously explored. Obviously, efforts in the new millennium, in which the Internet has tremendously grown in importance, are not described because of the publication date. Nonetheless, the general trajectory of the field can be ascertained by this historical dive.

Indeed, history conveys ideas with extreme accuracy, so this book introduces readers to the field in an accessible way. Anyone looking to learn about cryptography from real-world methods can gain from this treatment. It does not enter into mathematical minutiae and leaves that to other introductions. Instead, as a history, it deals with pragmatics by an approach that non-mathematicians can appreciate. Singh has adapted this text into a later version that is directed to interested young people. Together, either of these books will orient curious readers about this increasingly important field. show less

Some of us never gave codes more than a passing thought beyond the comedy of Ralphie Parker’s Little Orphan Annie Decoder Ring in the movie A Christmas Story. Many of us never suspected that code-making and code-breaking have been such powerful forces in our own history, from the decipherment of ancient languages to the defeat of Nazi Germany to the development of the modern computer. An exhaustive study, yet never tedious, Singh’s talented prose transmits his own powerful fascination and enthusiasm for the theme to the reader, striking just the right balance in the challenge of coherently presenting the complexity of the subject while formulating its elucidation for a mass audience.

Much like how Mark Kurlansky makes a subject like salt interesting, Simon Singh makes all things code fascinating. From the very beginning The Code Book was informative and interesting. Peppered with photographs and diagrams, The Code Bookrecounted the events in history where the ability to break a code (or not) meant life or death. Beginning with Queen Mary of Scot's attempted plot to murder Queen Elizabeth on through the first and second World Wars. The only time I really got bogged down was, of course, when Singh would get a little too detailed with mathematical explanations of more difficult codes and ciphers.

Simon Singh's book on the history of cryptography is a brilliant work of popular science and history. The aim of the book is to take us from the days of simple hidden messages, through the invention of increasingly complex substitution ciphers, modern codes and into the types of codes (and methods of breaking them) that we might see in the future. As someone with an interest and history and puzzles, this book was an absolute delight.

There are two things in particular that Singh does very well. First, he masterfully layers the increasingly complex codes one on top of the other. This allows him to take the time to explain each idea clearly, and then use the prior codes to introduce the new ones. It is easy to imagine an author losing the show more audience very quickly in a work like this. If one does not understand the notion of a 'key' in some of the earlier substitution ciphers, then the RSA encryption standard will be utterly incomprehensible. That is, even if the central idea of RSA was explained clearly, it still rests on the ideas that came before it. Losing the readers at any stage along the way could have resulted in an overly complicated second half.

Singh hits a pitch perfect pace. He typically provides an initial explanation of idea in cryptographic terms, before using simply toy analogies, before returning to the more complex explanation. As a result, the toy analogies are frequently illuminating (the reader knows what to look for). It was also never plodding. There was no point in the text where I found the ideas or explanations difficult to follow, and the questions I had were based on the subject matter, and not Singh's presentation of it. This is a book that any reader will learn a great deal from.

The second thing that Singh does very well is situate the codes historically. Each of these codes is tied to an interesting story - whether a treasure hunt or the execution of a monarch. Singh is able to weave these stories into the tale of the codes, which makes for compelling reading at two levels. I have a great interest in Turing in my professional work, and I was delighted to see his moving story recounted here. The high stakes of codebreaking adds a real sense of urgency to the more technical discussions covering the back and forth between codemakers and codebreakers to develop ever better codes.

Indeed, the only chapter that did not quite hold up to the same quality as the rest of the book was his coverage of the political debates surrounding encryption. It is indeed a really interesting issue whether encryption is a bastion of free speech, or a tool to enable illegal and violent acts. Singh wants to stay above the fray, and just outline the two positions. All we end up getting is a rather simple overview of the conflict. This is a philosophical and moral question, and requires a different approach. Indeed, I would have preferred Singh to take a stance on the question. It would have helped him get into the details of the arguments, which would have been more illuminating (even if the reader disagrees) than the "one side says x, one says x" approach he adopts.

Despite my quibbles with this chapter, I found this to be an admirable work of pop science and history. Singh tells a fascinating story in a way that does not oversimplify. At the same time, he is able to explain the subject matter clearly. Any reader with an interest in history, puzzles or codes will find a lot to enjoy in The Code Book. show less