Here's a Bombe we can all welcome

Enigma fascinates me. 

Not just any enigma, although they are pretty interesting too.  Enigma was the breadbox sized cipher machine used to encrypt messages (most famously) by Nazi Germany during World War II.  I’ve even downloaded and played with a simulator to encode my own messages.  It’s very cool, just for it’s own sake. 

A very brief explanation is that it made code sorta like A=1, B=2, C=3, etc.  Except it doesn’t take much of a rocket surgeon to guess what’s going on.  The Enigma worked because it could change the codes, and so long as the sender and receiver knew where to begin setting their wheels, they could read the message.  So the Enigma may say A=1, B=2, C=3 one time, and the next day it would be A=21, B=3, C=12.  The whole arrangment could change and it would be very hard to figure out.

Psst:  Want in on a secret?  The British figured it out.  Hey, I think it’ll even help those Limeys win the war. 

The British worked out how to use a crazy machine - an “electromechanical device” to crack the code.  They called it the Bombe and that image is what I think of when I think of passing secrets in code.  It was one of the very first computers - although it had almost nothing to do with the computer you’re using to read this with right now because it was Top Secret until the 1970’s.

It started off with the work of a Polish cryptologist (“math whiz”) Marian Rejewski.  His work was later used to create the British version, created by Alan Turing and Gordon Welchman.

Simply, it worked by being wired like the Enigma machine, except it had a motor attached to the wheels.  Instead of turning the wheels to encode a secret message, the Bombe spun the rotors to get possible guesses as to what the message could be.  It made it much faster to get possible messages, although it was also faster to find a blind alley.  Speed was of the essence of the war, though, and the British used it well to gain the advantage.

John Harper led the reconstruction of the Bombe machine.  My hat goes off to you, John.  You’re every bit the hero that Alan Turing and his compatriots were in my eyes.

Heavy duty reading worth the time can be found in this thread.