Technology & The Enigma Machine

The Enigma machine is actually one of the best thing I ever seen in my life... I know now is just an antique, but at the time it was one of the most incredible devices ever builted for its complexity, the extreme safeness of its encrypted messages and its handiness.

Exploded structure of a rotor

Let's dig a little bit deeper into this machine: the principal compontents of the first machine presented by Arthur Scherbious consisted of  a keyboard, a plugboard, 3/4 rotors, a reflector and a lamp display pannel.
The machine workedpretty much in the following way: the operator press a character in the typewriter starting an electric impulse that is going to follow a certain pattern which is swapped when it passes into the plugbloard, then it goes trough the rotors, come back thanks to the reflector and it light a lamp wich corresponds to a certain letter (result). Explained in that way it may looks that it is an easy code to break, but there is a lot more going on in that machine... in fact the rotors are not fixed in that position, but they change at each pression like the odometer does, meaning that the first rotors moves each   time, meanwhile the second one makes a step only after the first one has done an entire cycle, and the third one does the same with respect to the second one, moreover the plugboard disposition could have been changed and the first position of the rotors choosed freely. To sum up with all those basilar elements the machine already disposed of a number of possible combinations way big to be discovered in useful time.

Schematic representation of the classic enigma operation

And that it was just the classical machine, if we also consider the additional complexity given by the appendix devoloped later in time (which you can find in the previous post Secret Services & Patents: The Enigma Machine)  the number of possible combinations increases exponentially..

Here you can find other information about what was new in each evolution of the machine:

http://www.cryptomuseum.com/crypto/enigma/

And in this one a programme that simulates the operation

http://enigmaco.de/enigma/enigma_it.html

And now a little bit of humor...

The argument of this post is related to the one contained in Secret Services & Patents: The Enigma Machine

Sources:
[The Code Book, Simon Sing];
http://ciphermachines.com/enigma;
http://en.wikipedia.org/wiki/Enigma_machine;
http://www.bletchleypark.org.uk/content/machines.rhtm;
http://www.codesandciphers.org.uk/enigma/;