If anyone finds this intriguing and happens to be in the DC Area, the NSA's crypto museum has 2 Engima machines and one of the US built bombes (which used a mod

If anyone finds this intriguing and happens to be in the DC Area, the NSA's crypto museum has 2 Engima machines and one of the US built bombes (which used a moderately different design than the British ones). The bombe exhibit is cool, but the enigma machines are a highlight because you can actually use them. Because encryption and decryption are the same function (kinda like CTR mode), it's pretty easy to generate a string of gibberish that makes the display light up with profanity (don't forget to roll back the rotors). Fun for all ages!