How they cracked the Enigma code

If you are even mildly interested in history, then I’d wager you’re interested in World War 2. And if you’re even mildly interested in cryptanalysis … well, if you’re mildly interested in cryptanalysis, you probably refer to it as codes, or code-breaking. Well, if you’re mildly interested in code-breaking, then you’re probably aware of the German “Enigma” machine from World War 2.

It was supposedly unbreakable. And, if you watch garbage movies like U-571, then you probably think that some heroic Americans captured a machine without the Germans knowing, and from then on, everything was hunky-dory.

Wrong! Don’t trust Hollywood.

The real World War 2 was not Americans vs. the Japanese and the Nazis, it was a WORLD WAR, with a multilateral for called the Allies. /rant

Anyway, if you’re interested in a full and complete history of how the Allies broke the Enigma code, have I got a story for you. Hint: The Americans did play a part, as did the British. But no one could have done it without pioneering work done by Poland.

Poland? Weren’t the out of the war in the first two weeks?

Yup, but before the war even started, they were making huge strides on cracking the German codes:

Marian Rejewski determined the necessary complicated mathematical equations to determine the wiring of the Enigma rotors. Initially, there were too many unknown variables. With the information Hans Schmidt sold, Rejewski filled in some of the unknown values. After several months of analysis and work, the Polish mathematician determined the wiring of each of the rotors. Thus, they completed the first of the difficult tasks in reading the secret Enigma messages.

With some brilliant analytic work and some guesswork, Marian Rejewski also determined the wiring of the machine itself. Originally, he assumed the electrical current coming from the first letter on the plugboard (Q) plugged into the first position on the input drum (A). However, when this repeatedly failed to work, Rejewski tried another easy configuration that proved to be correct. The Germans connected the plugboard to the input rotor alphabetically. Later, when the British learned of this simple connection, they were astonished. They had never tried an alphabetic connection in their early attempts to break the Enigma.

The (lengthy) piece also gets into some of the early development of the computer, which is tied into code-breaking.