Friday, January 9, 2015

Fake history - ‘The imitation game’ movie review

Alan Turing was a legendary mathematician and a pioneer in the field of computer science. During WWII he worked for the Government Code and Cypher School, analyzing and solving Axis codes. His main achievement at GCCS was the solution of the plugboard Enigma, used widely by the German armed forces. Turing was undeniably a genius and after the war he continued his research into computers but in 1952 he got in trouble with the authorities after a police investigation into the break-in of his apartment revealed that the culprit knew Turing and had a homosexual relationship with him. Since homosexuality was a crime both men were convicted of ‘gross indecency’ and Turing had to undergo hormonal treatment. His conviction affected not only his personal life but also his professional opportunities. In 1954 Turing was found dead in his apartment, apparently the victim of cyanide poisoning. There is speculation on whether this was an accident or a suicide.

From the information presented so far it is clear that Turing was a fascinating individual and a movie about him was long overdue but is ‘The imitation game’ up to the challenge?


What I expected to see
Since I’ve read quite a lot on WWII cryptology and signals intelligence there are some events that I expected to see in the movie, not only because they would add realism to the film but also because they prove that truth is stranger than fiction. What are they?

Polish codebreakers: In the 1930’s the British and French codebreakers, despite their best efforts, were unable to solve the plugboard Enigma. If countries with great resources and a long tradition in cryptanalysis could not solve this device one would expect that no one else could have succeeded, especially a smaller country with limited resources. Yet contrary to all expectations the Polish codebreakers had not only managed to figure out the operating principle of the Enigma but had succeeded in retrieving the rotor wrings and then solved the internal settings of several networks. They managed to keep this a secret not only from the Germans but also from their close allies! They only revealed their success to the French and British representatives in July 1939 and thus helped them immensely in their codebreaking work.
Gordon Welchman and the diagonal board: Welchman was a talented mathematician who worked on the Enigma with success, eventually running Hut 6, responsible for German Army and Airforce Enigma trafffic. Welchman’s great contribution was coming up with the idea of the diagonal board. Turing’s bombes were modified to add the diagonal board which made them much more efficient in their operation. As Gordon puts it in ‘The Hut Six story’, p304: ‘Turing, though initially incredulous, was quick to appreciate the importance of this new twist in Enigma theory, which greatly reduced the number of bombe runs that would be needed to ensure success in breaking an Enigma key by means of a crib

Naval Enigma – Lofoten raid: By 1940 the British codebreakers were routinely solving current Enigma traffic, mainly from Luftwaffe networks. Against the naval Enigma however they had made little progress because the device was used in a more secure manner (additional rotors and use of enciphered message indicators). By March ’41 their only operational success had been the solution of the Enigma ‘key’ for 5 days of 1938 and 6 days in April 1940. In order to force this deadlock the Brits decided to put statistics on the side and use brute force instead! In March 1941 a commando raid was mounted against the German forces in the Norwegian Lofoten islands with the goal of capturing Enigma cipher material (monthly keylists and indicator tables). This operation was a success with material retrieved from the German armed trawler Krebs. This material allowed Hut 8 to decrypt the February traffic during March. Then thanks to the intelligence gained from this ‘break’ they were able to solve the April and May traffic cryptanalytically.
4-rotor naval Enigma/4-rotor US bombe: In February 1942 the U-boat command stopped using the 3-rotor Enigma and instead introduced a modified 4-rotor version. This was much more secure than the 3-rotor version and immediately put an end to the British success. British and American efforts to solve it failed again and again. By December 1942 only 3 days traffic had been broken. This failure had strained relations between British codebreakers and the US navy’s OP-20-G. It was obvious that new 4-rotor ‘bombes’ were needed but the British reassurance that these would be soon introduced failed to materialize. The Americans then decided to build their own ‘bombes’ at the National Cash Register Corporation under engineer Joseph Desch. It was a good thing they did because the British 4-rotor ‘bombe’ design turned out to be problematic.

Are these events mentioned in the actual movie? Let’s see.
‘The imitation game’

The movie starts with the police investigation in 1952 and then takes us back to 1939 when Turing first visited GCCS. There he had to solve the Enigma while facing the hostility of Commander Denniston and the other cryptanalysts. Everyone thinks that Turing is a failure but eventually his ‘wacky’ idea to build a machine in order to decode a machine finally works and immediately the British know of the location of every German U-boat in the Atlantic. However they decide not to sink them all because that would alert the Germans. In fact Turing stops them from notifying an Allied convoy of an impending attack even though the brother of one of his fellow cryptanalysts is on board. Turing with the help of Stewart Menzies keeps his success with the Enigma a secret from the military authorities and also from Commander Denniston because he fears that they will misuse it. Instead he decides to use statistical theory in order to find where the Enigma intelligence should be used to have the best effect on the war effort. Having won the war on his own Turing then goes back to teaching and the movie shows how much he suffered from the police investigation and the hormonal therapy, leading to his accident/suicide.

The movie is definitely entertaining with great actors, great sets, great cinematography etc. However the storyline isn’t just exaggerated in parts or simplified for the general audience. We’re talking about huge errors and strange conspiracy theories being shown to viewers who probably don’t know any better.  
Am I exaggerating? Someone can counter that it’s not a documentary, it’s a movie. Let’s have look at the failures of the film in more detail. Grab a beer, coffee, tea, whatever works for you because you’ll need it…

Alan Turing = part nutty professor part rain man
Turing definitely wasn’t an average person and obviously had his idiosyncrasies, however the film makes him look completely helpless in his interactions with other people. Maybe the producers thought that the average viewer would only appreciate how smart Turing was by making him autistic.

Bletchley Park = Four guys and a pub
I thought that Bletchley Park was a huge organization with thousands of people working on Axis codes. Apparently I was wrong. According to the movie Bletchley Park consisted of four cryptanalysts (Turing included) and a rather homely pub. Oh, there’s also a storehouse where they keep the bombe ehh i mean ‘Christopher’.

Turing = MacGyver
Some books claim that the bombe was built by Harold Keen, the chief engineer of the British Tabulating Machine Company based on Turing’s designs. These books are wrong (according to the movie). The bombe was built by Turing himself with no assistance from anyone else.

Where are the Poles?
I’ve said earlier that the first to succeed with the military Enigma were the Polish codebreakers. For some reason the movie doesn’t acknowledge their success. When at the beginning of the movie Turing meets Commander Denniston he is told that everyone considers the Enigma unbreakable. This is after September 1939 because in the first scenes we hear the declaration of war between Germany and UK. Yet in July 1939 the Polish had revealed their success to the Brits and French.

Later in the movie when MacGyver Turing is building his bombe he says that his machine was inspired by an old Polish machine but is infinitely more advanced. This is not explained further nor is any reference made to the Polish solution. In fact the Turing bombe was not necessarily infinitely more advanced from the Polish device, it basically worked on a different principle.

Where’s Gordon?
Apparently Gordon Welchman never existed. However the diagonal board is mentioned once without explaining how it works. In the movie it is discovered by Hugh Alexander.

Turing industries: Build first - figure out how it works later
In real life Turing came up with the idea of exploiting a ‘crib’ (suspected plaintext in the ciphertext) in the Enigma traffic and built a device around that idea. In the movie Turing starts building the bombe as soon as he arrives at Bletchley Park. Yet he only figures out cribbing much later thanks to Joan Clarke!!! What was he building all that time?

Where are the Americans?
The movie doesn’t make any reference to the new 4-rotor Enigma introduced in 1942 in the U-boat command. No mention is made of the technologically advanced US 4-rotor bombes.

The Enigma panopticon
According to the movie once they finally solved the settings for a day they easily found the locations of all the enemy submarines in the Atlantic. No mention is made of difficulties in interpreting messages, delays in decoding, lack of traffic or failure to decode. Yet decoding naval messages didn’t mean that someone could get their coordinates since they were enciphered with a manual system before being enciphered once more on the Enigma. As I’ve written in B-Dienst vs Bletchley Park - The invasion of Norway and the Battle of the AtlanticCoordinates were taken from a grid table. From June ’41 coordinates were further disguised by using fixed reference points on the grid table. From November ’41 an Adressbuch was used to encipher the grid references’. The coordinates problem was only mastered by the Allies in June 1944 when they captured an Adressbuch from U-boat U-505.

Conspiracy theories
The biggest problem I have with the movie is that it repeats some strange theories that probably belong in a conspiracy forum rather than a serious film.

The first one is that the Allies only used Ultra intelligence when their statistical theory??? showed that it would have a big impact on the war situation. In the film they show a whole convoy being abandoned to the U-boats because had they changed its course the Germans would have found out about Bletchley Park. In real life Ultra intelligence was used on ALL fronts. Every measure was taken to ensure secrecy and only the top commanders were fully indoctrinated into the secret but the intelligence WAS used. For example what did the Brits do when (thanks to captured keylists) in summer 1941 they started solving U-boats messages with little time lag? They rerouted all their convoys around U-boat concentrations. Only 5 of 26 SC convoys, 2 of 31 HX convoys and 3 of 49 ON convoys were attacked…
The other weird theory promoted by the movie is that the Soviet spy John Cairncross was known all along to the British security services. In fact Menzies tells Turing that it was him that allowed Cairncross to come to Bletchley Park so that he could send valuable intelligence to their ally Stalin. I guess no one can touch those British superspies. They can never lose. Even if you manage to get a spy into their organizations it’s only because they know about it and they allow it….

More mistakes
From the first scenes it’s clear that Commander Denniston doesn’t like Turing. He really, really doesn’t like him. Perhaps Turing fought for the Starks…

When the Enigma device is first shown Denniston says that Polish intelligence smuggled one out of Berlin. Nope. The first Enigma was captured in February 1940 from U-boat U-33.
The movie shows Enigma being used by U-boats, which is correct but it also shows Luftwaffe bombers sending messages which is not correct. Aircraft used hand ciphers for sending messages.

A U-boat is shown attacking warships while underwater. Not accurate. U-boats usually approached on the surface and their main goal was to sink merchant ships not warships.
The movie says in the beginning that thanks to the U-boats Britain was starving. Bullshit.

When Turing decides not to use the Enigma intelligence in fear of alerting the Germans Keira Knightley says: ‘they’ll have changed the design of Enigma by the weekend’. In fact the Germans were planning to replace the Enigma with a new device during the war but they never managed it due to production problems.


  1. Thanks for the interesting & detailed review, Christos.

  2. 1. It's standard garbage, trying to create "drama" regarding maths. The moral dilemma about saving the convoy is absurd, he wouldn't know where his brother is, wartime secrecy.

    2. I do not mind the historical inaccuracies (maybe I watch too many fifties movies), but it is internally inconsistent. If you're going to tell a story, tell it well. In the beginning, they are already aware of known plaintext attacks on Engima, and use it to break some messages. They build a machine, but it in no sense is aware of what it's looking for. Then they realize that they could search for the key of a single message.

    3. "Bletchley Park = Four guys and a pub" Erm. I accept that most movies don't quite have the budget to have a real cast of characters.

    4. Replacing Engima? Any information on this replacement machine?

    1. They had two systems in development. Cipher device 39 - SG 39 which was similar to the Enigma (had 4 rotors) but with 3 additional ‘Hagelin type’ rotors to make wheel movement irregular plus rewirable entry rotor and reflector. The other was a small device with sliding alphabets and ‘Hagelin type’ wheels called Cipher box - Schlüsselkasten. It was supposed to replace Enigma.