A device that looked like a typewriter that the Germans used to create coded messages. They truly believed that the codes were unbreakable but once the allies got their hands on some examples and some code books they got craking on developing machines to decode German transmissions.

Let me start with some background. Industrial spying is and was common in the past. Companies are always trying to discover what their competition is doing. In the period before World War II an American invented a machine that would make a code that was "impossible" to break.

The machine was unable to get much, if any, interest in the United States. However the German Post Office (before Hitler) bought a few machines. (I do not know what they did with them.) Somehow, and sometime, the German Army found out about them and by the time Hitler was in power they became very popular. The were not common in the early years, but by 1939 there were quite a few of them manufactured in Germany and being used by the German military forces (Army, Navy & Airforce). The machine was given the name "Enigma," meaning a puzzle that cannot be solved.

Polish experts had stolen one or two machines before Hitler invaded Poland, and they had some incredably intelligent mathmaticians that were able to break the code.

Poland then shared the machine with the French, and later they shared the machine with the British. Owning a machine would not help a person break the code, so while it was nice to see how the machine worked, it was still not enough.

Basically the machine is an electric typewriter. BUT when you push the letter "A" it sends and electircal signal to a wheel. Wires inside this wheel will connect it to some other letter, say an "N." But that wasn't the end of it either. That "N" now sends it to another wheel that again changes the letter, and then again to another wheel that again changes the letter.

That is not complicated enough. Each of the wheels rotates each time you push the typewriter key. So and "A" with one push might be an "N", but the next push the "A" becomes an "X" and the next push a "T" and so on for 26 or more changes.

That is STILL not enough, because there are things in the back of the machine that allows even more changes.

So to receive the message someone sends to you a person much know the exact settings of each of the three wheels, and the wiring in the back. Only then can you push the letters you have received and turn them back into the original message sent.

Hope this helps. P.S. The British invented the fist computers so they could break the codes, even so it wasn't always easy.

==

The German Enigma was recovered by American Forces in TICOM (Target Intelligence Commitee [closely related with NSA]). In addition to capturing a few of the machines, they also captured some soldiers familiar with the machine. The soldiers told them the principles behind the machine, and American scientists, engineers, and agents were able to reverse engineer the machine to see how it worked.