Enigma Wheel

How many starting positions does the Enigma Wheel have?

Remember that the wheel moves clockwise after each letter. Why does that make the code harder to break?

If you know the message begins with ‘the’, how could you use that as a clue to break the code?

Our Enigma wheel is a simplified version of the machine used by Nazi Germany in World War II. The Enigma machine was a very hard code to break.

One reason Enigma was so hard to break was that, after coding a letter, the wheels would move forwards, which changes the code. So, code breakers could no longer use clues like looking for the most common letters. The other reason Enigma was so hard to break was because it had so many starting positions. The real Enigma machine contained three wheels (chosen from a box of five) plus more wires at the front of the machine which needed to be plugged into the right places. Altogether, there were 158, 000, 000, 000, 000, 000, 000 ways to set up the machine. Far too many for code breakers check by brute force!

During the war, British code breaker would guess a word, or a phrase, that might be in the coded message. They then used large code breaking machines to search for a position that made their guess true.