Not the Enigma, but actually a special version of encryption created for Hitler to communicate with his top generals with an “Unbreakable” Cipher. The group of people that broke the code, did so without ever seeing the machine. This is a fantastic example of extreme reverse engineering and gumption. It went on to inspire the first real computer Colossus.
Mathematician James Grime takes you through how and why this machine was harder to crack than the famous Enigma.