“The Code Book” by Simon Singh (Doubleday, 1999)
Winston Churchill was so pleased with the British success in getting hold of German cryptographic material in World War I that he boasted about it in his book The World Crisis, published in 1923. The Germans were goaded by this admission into spending the next ten years constructing what they believed to be an unbreakable cipher machine – the Enigma. Interpreting the German radio messages during World War II was such a critical contributor to Allied victory that some commentators believe that the war could have gone on for years more, or even been lost. Thus Churchill made sure that the Enigma story remained secret, with the result that he and other commanders were able to write their memoirs in a more flattering light than they probably deserved. All equipment at Bletchley Park in the UK (where the decoding took place) was destroyed, and some of the stars died before the secrets began to be divulged in 1974.
All this Simon Singh recounts in his very accessible Code Book, which has the knack of explaining very lucidly how encryption and decryption have evolved over the centuries, as well as weaving a gripping story of the historical events they triggered very felicitously into the text. He opens the book with the story of Mary Queen of Scots, encouraged by her English captors into encoding treasonous plans in a cipher that had already been broken, and he brings his readers up to date as far as the Navajo code-talkers in WW II, who made up for the clumsy mobility of the U.S.A.’s unbroken SIGABA machines, and have been highlighted in the successful movie Windtalkers since the book was published. He describes the current state of encryption techniques, presenting the case for greater control over cryptographic techniques – largely held by the National Security Agency – balanced by the libertarian/business one of claiming that access to such means is critical for individual liberty, for the growth of electronic commerce, and for the protection of commercial secrets. Finally – in what is a more demanding chapter – he outlines how quantum computing and cryptography will conclude the battle. “The codemakers will emerge victorious” (over the codebreakers).
Singh’s dual objectives in the book are to “chart the evolution of codes,” and “demonstrate how the subject is more relevant today than ever before.” He succeeds with the first objective better than the second, although he says very little about the (reportedly indestructible) Allied codes of World War II, and the story quickly moves to more theoretical issues thereafter, with few anecdotes. He gets a little starry-eyed with the promises of Internet-based commerce, and probably misjudges the perspectives of the ordinary public about what substance they will send in their emails. And the book (whose title is weak), is actually sub-titled “The Evolution of Secrecy…”. which is really a different topic.
In one telling sentence, Singh unwittingly anticipates September 11, and inadvertently identifies a challenge that he could have explored further. “If there were to be a series of terrorist atrocities, and law enforcers could show that wire-taps would have prevented them, then governments would rapidly gain sympathy for a policy of key escrow” {i.e. holding critical keys for use in an emergency}. The dreadful irony of September 11 is that it appears to be more of a failure of interpretation and execution, than an inability to collect the right information. Stalin and Hitler were notorious for discarding “negative” intelligence reports if they did not fit in with their own perspective, and our own democratic culture provides similar obstacles to protective action. But the study of that failure is another book.