The success for cracking the Enigma machine really comes down to the work of this man, Marian Rejewski. Marian Rejewski was a Polish mathematician who worked on the Enigma machine in the early days of the 1920s and 1930s. The Enigma machine was actually originally available as a corporate machine; you could go out and buy it as a corporation, and use it to encrypt and store data. And so it wasn’t until much later that was taken over by the German Nazi Party and used in their war efforts. And so public Enigma machines were available and could be studied. And so Marian Rejewski was able to study some of the early Enigma machines and try and predict the adaptations that Germany made as they move closer to war in the late 1920s and 30s. So based on his work, he was able to determine what the Germans were doing and was even able to eventually replicate some of the German machines that they had created. But of course, that was just part of the story. So to crack the Enigma machine, it was really first cracked by Marian Rejewski of Poland. He was able to use some of those publicly available Enigma machines to crack some of the earliest things that they did. By 1938, as Germany was getting closer to war, they added two new wheels of their own making it much much harder to crack if you didn’t know the wheels existed. And so Marian Rejewski of Poland contacted folks in England and gave them a lot of his research and ask them for assistance. And so by 1939, Alan Turing, working together with the folks at Bletchley Park, created what he called the Bombe, which was a machine that could decrypt the Enigma machine. And so work on the Bombe progressed pretty much throughout the entire war. And by 1945, almost every single message that the German sent using the Enigma machine, could be deciphered by the allies within two days. So what is the Bombe? The Bombe is a machine developed by Alan Turing to simulate hundreds of Enigma machines side by side. You can see that it has all of these sets of three wheels, simulating the three wheels that might be present in an Enigma machine. And it was designed to explore many of the weaknesses and other facts about the Enigma machine that were known to the Allies based on the work of Marian Rejewski and Alan Turing at that particular time. So let’s take a look at a quick video of a Bombe in action just to see what it looks like.