Friday, 22 June 2012

Happy Birthday Dr Alan Turing, a brief history of the Enigma code

As road trips goes I liked the excellent one I went to on a few years ago, it was a world war two adventure.
My friends and I travelled to Duxford a aircraft museum a much needed visit on all things war related.
later we visited Bletchley park a guarded secret of world war 2 until recently, when files of the worlds first code breaking computer was locked in a government cover up ordered by Winston Churchill himself.

In 1919 a Dutchman Hugo A. Koch  and a German Arthur Scherbius independently devised a writing machine. Scherbius eventually brought Koch's patent and combined the two machines together, later in 1926 the German Navy Brought a machine which eventually became Enigma. I the machine at the time was for sale on the open market. American cryptanalyst William F. Friedman broke japans code but could never solve  Germans variations of Enigma.

The polish could easily break germans code until they found the Germans brought Scherbius Device.They set work buying the machine so that they could decode Germans enigma code. Through certain memos they had work out the modifications and internal wiring Of the Enigma machine. though each arm of the German military had its own modifications to the Enigma Machine.

Also soon after the Germans would add a pass key for each message, they used tricks like using the letter 'Y' as a fullstop and would rotate or mod the machine every month or so. This proved very difficult to crack, the polish solution was to buy 6 machines connected together and try every permutation to find the correct message. this collection of machines was called a Bombe. With the Germans about to invade Poland the Polish had no choice but to share their findings to the British and French Allies.
Within weeks of arriving at Bletchley park Alan Turing had specified an electromechanical machine that could help break Enigma more effectively then the polish Bombe. The Bombe with the enhancement suggested by Gordon Welchman, became one of the primary tools used to attack enciphered messages. Turing used a theorem in logic to substantiate the inner workings of the Bombe.
In 1942, Turing devised a technique Turingery to use against the Lorenz cipher, these were messages produced by Germans new secret writer machine. It was a teleprinter rotor cipher attachment which was given a name of tunny at Bletchley Park. The new machine used a new system of cam settings of tunny wheels which required a new Tunny team. Max Newman and Tommy flowers. built  the worlds first Programmable digital electronic computer the "Colossus". This was built to replace a simpler machine which was named "Heath Robinson" after the cartoonist who would draw crazy unlikely machines. The new colossus machine was a break through in technology, it correlate two streams of data one was the enciphered massage stream and the other was the carefully matched patterns of the Lorenz machine.

While the older Heath Robinson machine would have to have two simultaneous paper streams with data  on the paper being optically read. The old machine would need to synchronize its paper streams for it to work.
While Colossus would just need one paper date stream and the other would be stored within its circuits as jumper cables on a plug board configuration.
The colossus reduced the time of breaking the lorenz massages from week to hours. This was helpful in the run up to the D Day landings, as Hitler was convinced the attacks would be in Calais and not 400 miles away in Normandy. The number intercepted messages increased, when as a united effort of the french resistance and allied forces knocked down the teleprinter lines. This forced the Germans to use radio communication.

Alan Turing was instrumental in cracking the encrypted messages, he developed ideas in the Field of non linear biological theory, which paved the way for complexity and chaos theories.It is generally accepted that the Turing machine concept can be used as a model for today's digital computers. Turing went on to define the aspect of artificial Intelligence. In his thought experiment of a conversation between two hidden entities. this requires a level of understanding which one human trys to determine if the other entity is human too.

My trip ended with a fond look at the secret history of code breaking, but now throughout this year lots of event are happening to celebrate the great man who is being called the father of computing. As an end user I must admit its makes a interesting story to read about the development of the principles of computing. If not I might even rent out the 2001 film "Enigma" just to celibate the guy. But I digress the 23rd of june marks his birthday and I'll just say happy birthday Dr Turing. And as predicted I'll be using a computer to play one of the fine first person shooters I have on the hard drive.

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