After viewing The Imitation Game recently, I decided to create a cryptography challenge based on the German ENIGMA machine.
In order to see how much of a challenge this really is, I will start not with the 4-rotor naval Enigma that Alan Turing cracked in the movie, but with the basic 3 rotor machine as it appeared in 1938. I will only use rotors I, II, and III (but in random positions), and I used exactly 10 wires on the Steckerbrett as was common procedure. I used a random number generator to choose the wheel location, starting position of the 3 wheels, the ring positions, and the wiring of the plugboard.
Since this will be the only message I am generating with this key, I will not add a session key at the beginning. I will certainly not add it repeated twice. :)
For a crib, you may assume that the plaintext contains "THIRTY". I did not do anything evil such as translating the coordinates to German.
OYXNE NHRII GPIPM DNUYQ MXVKQ VSQZA PRNJY JADTX UNPLD JIJJM HAASM HLYFJ RNEBA ASJOG SBXVO MXNRC DKNDE KHLJK BDKEG UVWUG CEAQJ LLSBX BVGMV CBOZJ QRUCU KQNIU INXLT Y
As Team Ottlet mentioned in his log, the original puzzle has an evil twist, which I added through carelessness. It was standard German procedure to use "X" in place of spaces, as the enigma had no way to encode characters other than A-Z. I was careless and included some Xes, but not others, making the hill climb scoring more difficult. To rectify this, I'm adding another encryption of the message. This has all spaces between words replaced with X in the plaintext. I re-seeded the random number generator to create the keying material (initial positions, ring positions, stecker wiring) as having two messages with the same key would open this to different forms of attack.
UIVBI SCEAU YJABO KBCTG DTWLA ODFUN WCTAY DLNEV QKFPS JDNDP KMYKN GHVJE BEPJI XNEQL DDTWF PKZAX SFDLK PNCYT MZOOJ LQVLY QASUI LNJXS KHFWM CASVP KADUI VIMGU ISONF UWTVV FKAUH JZMMW
I am including a certitude link, although you will almost certainly not need confirmation when you have correctly decrypted the message.
Congratulations to Team Ottlet on a well-earned FTS/FTF
You can validate your puzzle solution with certitude.