Alan Turing


October 2014



Alan MathisonTuring


(23 Jun 1912 – 7 June 1954)




           We all know the famous adventure of the ENIGMA code-breaking and how much it contributed to the Allied success. The Bletchley Park heroes have their own special position in history, although very few of them became widely known figures.  


Their top hero, Alan Turing, the one who conducted the code-breaking and succeeded enormously in guiding the entire team working for the British SIS, had at least his name appearing after some decades the war was over. Alas, not because he was decorated or received any distinction, neither because he was the father of digital computers and the forerunner of artificial intelligence. His life after the war was actually never mentioned and his last days even less if not at all.


That was because Alan Turing was persecuted as criminal by law, due to his homosexuality. The worst, however, crime was conducted by his own country in the 50s. He was chemically sterilized by similar methods the Nazis used to sterilize German Jews for racial reasons back to the 30s! Eventually this lead Turing to a miserable situation and he preferred to end his own life instead.










The super-genius WW2 code-breaker and father of the computers that died as a criminal







Alan Turing memorial statue in Sackville Park, Manchester



Alan Mathison Turing was born in Paddington London UK from parents of Scottish and Irish descend. He spent his childhood in Hastings, at Baston Lodge, Upper Maze Hill, now St Leonards-on-Sea.

By 1927 Turing showed a remarkable ability in advanced math problems without having studied even elementary calculus. In 1928, aged 16, Turing encountered Albert Einstein's work ; not only did he grasp it, but he extrapolated Einstein's questioning of Newton's laws of motion from a text in which this was never made explicit.

He was charmed by the mechanism of Intelligence that lead him to the first definition of a modern computer processing

During World War II, Turing worked for the Government Code and Cypher School (GC&CS) at Bletchley Park, Britain's code-breaking centre. For a time he led Hut 8, the section responsible for German naval cryptanalysis

After the war, he worked at the National Physical Laboratory, where he designed the ACE, among the first designs for a stored-program computer. In 1948 Turing joined Max Newman's Computing Laboratory at Manchester University, where he assisted development of the Manchester computers[7] and became interested in mathematical biology. He wrote a paper on the chemical basis of morphogenesis, and predicted oscillating chemical reactions such as the BelousovZhabotinsky reaction, first observed in the 1960s.






Artificial Intelligence. The basics of a digital processor and programing - as stipulated by A. Turing








   It was just the middle 30s and Turing work on artificial intelligence lead to the most basic and revolutionary idea of what now we call the CPU or Central Processing Unit for a computer and eventually programming. Today it is considered almost trivial but it did not existed until the moment Turing has put it on paper. He imagined a long tape with symbols such as letters , or say 1 and 0 to make it simple , that passes through a ‘reader’ that feeds a ‘thinking unit’. If that units is made to react on a particular way, based on a particular pattern, then this unit can be made to do anything. This machine is basic and generic as described by Turing, it does not have any purpose to be put anywhere else than on a piece of theoretical paper but this ‘unit’ became the CPU, the paper tape with 1 and 0 became the memory, the RAM or ROM of today and the reaction pattern of this machine we know it today under the term programming. Again I say, today seems almost natural and unimportant, but it was Turing the first who put it on paper and promoted the idea as an axiom of the modern science of ‘Information Theory’.




The ENIGMA and Turing






   The working principle of ENIGMA was rather simple but extremely effective. It may be considered as an advanced Caesarian Code system where the alphabet is transposed in sequences so that letters in the original signal were replaced by other letters in the encoded one and the whole output message was becoming illegible. The decoder operator who received it had to know in what sequence he had to ‘replay’ the encoded signal to decode it and reveal the original.


   Imagine 2 keyboards, a classic one of a typing machine to input a signal. Then a second one where keys were replaced by lamps, the Lamp-Keyboard, where when a lamp is lit it would indicate the proper letter to be considered for the decoded letter inputted by the typing keyboard - drawing (1).  The changes or links between the encoded and decoded letters was achieved via a scrambler unit consisted of 3 (later 4) rotor teethed disks subdivided also in an alphabetical order and interconnected with cables. See drawing (2)



   According to how the rotors are positioned in the very beginning of the decoding an  initially typed letter , say Q as in drawing (1), would allow electric current run through the connections of the rotors following , say , the sequence Y , S , N , finally triggering the lamp over the letter N , on the lamp-keyboard. It was purely a decoding of the letter In which appeared in the decoded signal as Q - drawing (1)

After a letter was decoded the rotors would execute a one-letter rotation or shift so that the same letter will not be decoded by the same letter in the rest of the message. Otherwise a pattern was becoming obvious








   The setting of the rotors in the beginning was the very critical element of the ENIGMA. See drawing (3), where this setting is M, C, and L indicated on the windows next to the rotor tips. The operators had to know on each day at what sequence of letters they had to set the rotors at start. Using these settings it was practically impossible for a human being to identify patterns so that the coding method could be found. If however this settings were becoming known and if the enemy decrypt or had an ENIGMA machine to his disposal, then ENIGMA was becoming useless for the operator and extremely useful for the enemy!








   Such a machine, see drawing (4), was available by hundreds in units of the German army and navy even at meteorological stations and observatories. The first ever Enigma machine was actually copied by the Polish Information Service just before the war and was later given to the Allies after the war broke out. A settings list was later captured from a sinking German U-boat the U-110 (*). From then on the British who were working on this machine were able to know in advance many enemy moves. However, they were also reluctant to over-use it fearing that otherwise it was very easy to make the enemy understood his secret was compromised. In the meantime the ship losses for Britain became appalling while the Germans changed the entire list settings for added safety. This is when Alan Turing made his important contribution



(*) HMS Bulldog first captured a naval Enigma machine from the sinking U-110 in the North Atlantic in May 1941  The American film named U-571 who used the same ‘scenario’ was simply a fake and its story is a far cry from any historic truth








   Turing decided that he had to identify the internal logic of the code. His ‘machine intelligence’ experience was decisive. To gain over time of billions of human searches, he created a new machine, the so called Bombe – see drawing (5). Hundreds of sets of 3 disks were rotating day and night experimenting on thousands of combinations of German messages intercepted by radio, checking for any meaningful output. Even so, the billions and billions of possible combinations were making the use of a successful result very late to handle. Then Turing introduced a serious improvement: he created a number of impossible or possible results according to the particular subject which reduced the randomness of searches for Bombe. For instance during the bombings over England by Luftwaffe he understood that the targets were limited, usually to big cities only like say, London or Coventry and some RAF aerodromes. If on a similar signal pertaining to bombing he could identify these short-list names then the Bombe results were fast. It actually went on like this until the end of the war and the Allies were having now the upper hand. Many important victories were based on previous information decoded by Turing’s systems and in fact he had contributed very significantly to the war’s shortening. Apparently the Allies could not openly advertise their success. Some of those successes were kept well under the surface even for many years later for impressions created. One such is known to be the attempt against Rommel in Normandy due to the ENIGMA who decoded the date, hours and place of Rommel’s trajectory. Two Spitfires were sent for the rest. Years after the British did not want however people to know they attempted such a ‘murder’.




Turing persecuted as a criminal. He ends up by killing himself



   In his days in Bletchley Park, Turing developed an admiration to himself by his colleagues, mixed-up however with eccentricity. He was often coming to work semi-dressed in pajamas or wearing a gas-mask as a protection to hey fever.  He also proposed to a lady, Joana Clark, but soon declared his homosexual tendency to her. The relation kept on for some time but was eventually stopped. After the war he continued in Manchester University experimenting on the creation of the first electronic Computer, on those days with electronic tubes. It was the real leap forward to the work that provided the very first ever such machine ‘The Ace’. Although, huge and cumbersome, it introduced the first logic gates and was able of logic functions like AND, OR and could do some simple IF-statement decisions.

   There however he also found a notorious night-life where he met a young man, had relations with him but his lover has stolen some items from him, in particular a watch heirloom that belonged to his father. Turing was naďve enough to go to the Police asking to get it back but the Police was more interested in digging into his relations with the young guy. Turing, incredibly, described the details of the night he spent with this guy. The Police accused him immediately for homosexuality, a punishable act on those days.





The punishment for illegal homosexuality by the British Law was either a 6 year jail sentence or a chemical castration! 

The ‘execution’ was a daily injection of female hormones pills to Turing’s body in order to neutralize his male libido. The daily dosage had lasting effects which acted obviously against nature with immediate effect on his psychosomatic status which definitely drove him mad! In other words, it was at the end a mental attack on his brain and that is a brutal crime, especially to such a mind! He himself has commented that he helped Nazis lose the war because they were using similar practices with German Jews in the 30s and now he suffers the same thing by his own country.

The ‘political reasoning’ by the British State was that a homosexual genius that knew a number of war secrets was considered as a plausible victim of espionage recruitment in favor of the enemy, at that time USSR! Despite the plausibility of the case it is important to know that too many other traitors that spied for USSR against Britain were both homosexuals or heterosexuals but their motive was put either in the ideological area mainly or simply on the pure  financial one.



   This chemical castration was in essence a kind of death condemnation, and it did work as such. We may only guess that the contemporary story of the Cambridge 5 , the Philly’s team that betrayed England has added to such decision making due to 3 of them been homosexuals. However , their homosexuality was never the motive for spying to any of them but England did not want to accept the other option left to consider , that they betrayed out of pure hatred to their hypocrite and cruel ‘high-society’ against the poors of the mid-war years! Ironically, Turing’s death was not officially accepted as suicide. Another ‘unacceptable’ dimension by his punishing country. His body was found next to an eaten apple full of cyanide but the Police characterized it as … an accident. Turing has fallen into the trap of the ‘State Secrecy Reasoning’





A 2014 film on Turing – 50 years after his death



The Imitation Game (2014) Poster





Benedict Cumberbatch joined the project, Warner Bros. bought the screenplay for a reported seven-figure sum because of Leonardo DiCaprio's




The Imitation Game 







 BOOKS on Alan Turing:


·         Alan Turing: The Enigma by Andrew Hodges (5 Mar 1992)

·         The Man Who Knew Too Much: Alan Turing and the invention of computers: Alan Turing and the Invention of the Computer... by David Leavitt (1 Jun 2007)

·         Turing: The Tragic Life of Alan Turing by Fergus Mason (20 Jun 2014)


Watch on Youtube :   on Alan Turing’s life and work

·         The Strange Life and Death of Dr Turing - Part 1 of 2

·         The Strange Life and Death of Dr Turing - Part 2 of 2

·         Cracking ENIGMA

·         Turing: Pioneer of the Information Age


Watch on Youtube :   on ENIGMA


·         ENIGMA (film)

·         How ENIGMA operators & machines worked ,




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