[Cryptography] Turing Bombes Enigma

[Henry Baker]

FYI -- I guess these devices fall into the category of the "Internet of Cool Historic Things".

It is a fully functioning Enigma machine you can wear on your wrist.  This is a three rotor Enigma machine as used by German Wermacht in WW2 for encoding messages.  [So far as I can tell, it's the most useful wrist computer I've seen to date...]

http://www.asciimation.co.nz/bb/2015/03/24/a-three-rotor-enigma-machine-wrist-watch

Turing-Welchman Bombe completed.

http://www.asciimation.co.nz/bb/2015/10/04/bombe-completed

For those who haven’t been following the whole project basically I reverse engineered then build my own desktop version of the Bletchley Park Bombe, the machine the British used to help solve the Enigma code during WW2.

Thanks again to John Harper, who lead the BP Bombe rebuild team and who answered some questions for me, James Grime, mathematician and Enigma Expert, Magnus Ekhall who was one of people behind the online Bombe simulator, Frank Carter, who wrote the BP Report 4 booklet, and Bletchley Park themselves who managed to find and send me a copy of the aforementioned report that is out of stock!  Also the late Tony Sale who made available on his web site the US 6812th Division 1944 Bombe Report.

I started by making my own Enigma machine wristwatch because to understand the Bombe works you have to fully understand how Enigma works and how it was used operationally.

You can read about that here. [Link above]

My Turing-Welchman Bombe machine makes use of some software I wrote in C++ running on a Raspberry Pi 2.  I figured out for myself how the Bombe worked then wrote my own software version, initially in BASIC of all things to run on my homemade 6502 computer Orwell.  With the general algorithm worked out I ported it to C++.

The Raspberry Pi 2 connects to an Arduino which then drives three stepper motors, via driver boards, to turn the three indicator drums on the front of the machine.  These drums mimic the three indicators on the real Bombe.  The Arduino reports back the position of the drums to the Pi as a series of pulses then the Pi can tell the drums when to stop.  An LCD screen on the side of the machine mimics the original Bombe mechanical indicator unit as well as providing a basic user interface.  Start and Stop button are provided on the front of the machine as on the real Bombe.