Extract

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Chapter One

 

The Origins and Uses of Cryptography

What affected me most profoundly was the realization that the sciences of cryptography and mathematics are very elegant, pure sciences. I found that the ends for which these pure sciences are used are less elegant.

James Sanborn (b. 1945)

Prologue

One of the most frustrating of all cold cases in the annals of modern forensic science is the so-called Zodiac Killer one. The Zodiac was a mysterious serial killer who used Northern California as his killing ground in the late 1960s and early 1970s. The unknown murderer initiated the pseudonym of “Zodiac” himself in a series of letters designed to taunt the police and the media, adding to the mystery that he himself was obviously attempting to spin, as if he were writing his own version of a roman à clef. In several of his letters, the killer included four cryptograms. One has been definitively decoded, but three others remain unsolved and, presumably, hide the murderer’s real identity. ← 1 | 2 →

What makes the case particularly maddening is the possibility of unmasking the killer by decoding his seemingly simple ciphers. The whole case, actually, brings out the intrinsic connection among crime, mystery, and puzzles. The American writer, Henry David Thoreau, once remarked that, for some truly enigmatic reason, “We require that all things be mysterious and unexplorable.”1 Supporting Thoreau’s perceptive insight is the worldwide popularity...