CNET News Video
This is how the Nazi Enigma machine worksThe Nazis relied on the Enigma to relay secret communications, and the Allies' efforts to crack the code not only helped make D-Day possible but also helped kick off the computer age.
[MUSIC] Well this is the enigma machine,it's basically a typewriter keyboard with a light board. Now, the keyboard only has 26 letters. There's no spacebar, numbers, or special characters. And that was done on purpose because those kinds of characters would help give away the code. The way it works is quite simple, really. It's a typewriter. So you press a key that looks like a typewriter. And eventually a lightbulb lights up. And the lightbulb that lights up will light up a letter that's different than the key that you pressed. And so that's decoding. Now here is the German plugboard. Plugboard allows you to switch one letter to another. Let's say the E, if I press the E, and I want to change that E to a different letter, I would put that in here. And let's say I want to change it to an I, I would move it here. The second thing they would have to do is open up [MUSIC] This machine and here's the inner lid. And then here are the three rotors. And the way you would take those out is you have to release the pressure on them like this. And that looses them up so that now they can be removed. Each wheel has a notch, and that notch tells the next wheel next to it when to advance. One. And so, that notch is moveable. And the way you do that is you move this little lever out of the way, you can see it's now in position 4, which is the letter D. And I'm giving it a letter to move it to, let's say the letter 8. Now each one of these has a roman numeral on them, I through V. And I happen to have one, three and two here. And let's say that that's the position that you're told as an operator to put them, three, two, one. Now, I'm gonna put those in the machine. I would close this up. And the next thing I would do is, is I would set these on the correct position for the day. Let's say it's 5-10-15. So, I will put this on position 5, the next one on position 10, and the next one on position 15. And I can start taking and receiving messages. [MUSIC] Let's say I wanna send a simple message like hello. Okay, I've got my day setting, I'm all ready to go so I'll press first the H for hello. And I note the letter that lights up, it's a Q. Then I press the E, and a Q lights up again. Now, I'm going to press the L twice, and I get an E and a K. You notice that two letters lit up. I press the O, and then H lights up. So now I would give this message to the person that would send this. QQEKH. Now I'm the new operator, and now I'm gonna type in these letters. And note what letters light up. So I type the Q and a H lights up. I press again, now a E. Then I type the E letter and you see an L light up. I press the K and you see the L lights up again. Then an H and the O lights up. I just now decoded that message to the original message that was sent to me, hello. The beginnings of computing is directly attributable to the Enigma. If you have a hundred thousand people with a hundred thousand Enigma machines. All testing different settings of that enigma machine to brute strength break it. It would and they could do that test a different setting once a second. 24 by 7, it would take twice the age of the universe to break the code. So that's why the Germans had such confidence it wouldn't be broken. When you look at the technology that was available, they just did not foresee that Turing would invent a computer to break code. [MUSIC]