Chicago’s U-505 Enigma Machine

Fifty years ago this week, Gordon Moore published a paper that predicted our ever-expanding computer age. What became known as Moore’s law, forecast the doubling of the power of computers every two years. What began more as a guideline, has proven presciently true, the original forecast was for only ten years, now fifty years on it is still going strong. Moore and the computational revolution he foretold owes its existence in large part to the thinking of Alan Turing, who hypothesized the idea of an automatic machine, a thinking machine, epitomized by his self-styled Turing Machine. Turing was a mathematical genius and a bit of an ass. He broke the Nazi’s WW II Enigma code, but because of secrecy and other concerns, he was not recognized as the war hero that he was. Those other concerns include the fact that he was convicted of homosexuality, which was a crime then. I studied the Turing Machine in college, in the seventies. His groundbreaking research was hailed by my professors. Computer Science didn’t have much of a history, so it could ill afford to toss aside one of its founding fathers. Now, in more enlightened times, Turing’s reputation has undergone a renaissance. In 2013, the crown pardoned him posthumously for his crime of “sexual deviancy”. Last year, the Alan Turing biopic, “The Imitation Game”, was nominated for several Oscars. The movie told his code breaking story well, but incompletely, IMHO.

While little Gordy Moore was still undergoing puberty, Alan Turning was cracking the Nazi’s Enigma code with repurposed telephone exchange equipment, mathematics and his wits. A history lesson within this history lesson is needed here, so please bear with me. At the beginning of WW I the Allies captured a copy of ‘the’ German code book. The Allies were then able to read all of the German radio transmissions throughout the rest of the war and the Germans never suspected this until much after the war. Winston Churchill among others, later disclosed this secret to sensualize their own histories. This news caused outrage within the then nascent Nazi war machine. Admiral Doenitz, commander of the German navy vowed that this would never happen again. This is how the Enigma machine was born. The German army and air force also adopted Enigma, but never with the same rigor as Doenitz’s U-boats.

Turing and his crew, routinely broke the German army and air force codes, long before they could crack the German Navy’s code, such was the lack of discipline in the tradecraft of those two services. And it was tradecraft that cracked the U-boat code. As “Imitation Game” explains that routine 6 AM weather reports give today’s new code, with yesterday’s message, “All the German that you need to know is, Heil Hitler!” It is way easier to break a code if you know what is being said. This aspect of Turing’s code breaking strategy was adequately captured in the movie. My complaint deals with the “flaw” in Enigma and that it wasn’t highlighted in the movie. It would have played perfectly with the Turing persona. While the Enigma machine could freely substitute one letter for another, even changing the substituted letter again and again, it couldn’t substitute the original letter with itself. This minor flaw in Enigma was magnified by the German language, with its many words with repeated letters. German for weather is “wetter”. The two t-letters that aren’t T eliminate two, not one possible settings.