Bletchley Park
IXDS5503 - Media History and Theory Professor: Jason Occhipinti
Anthony Moore March 10, 2015
Government Code and Cipher School Bletchley Park in Buckinghamshire, England was a top secret facility for the British government during World War II. The urgency of the war and the rumored invasion of Britain by Nazi Germany led to key innovations in technology that were used to decipher encoded German military messages. These technological advances were critical to Britain’s national security and some historians estimate that the work conducted at Bletchley Park cut the war in Europe short by about two years. The secrets of the Park were unknown to the rest of the world until documents were declassified in 1974 which told its story. Obscured in the country side of England, Winston Churchill referred to the personnel of Bletchley Park was a rambling pile bought in 1938 to house the Bletchley Park as “my Government Code & Cypher School, run by British Intelligence. (Image 1) geese that laid the golden egg and never cackled.” (Keir 58) Because of its relative close location to London and its secluded setting, the British used Bletchley Park in 1939 to host its Government Code and Cipher School (GC&CS.) Upon arrival, the original staff at Bletchley Park found the grounds well landscaped and much of the 18th century avenues still in place. Small in number, the employees outgrew the capacity of the Park as their numbers soared above 10,000 men and (mostly) women. To accommodate their growing numbers, work began on huts that would house specialized units and by 1941 more than a dozen huts had been erected on the 58 acre estate. Hut 1 was used as a radio transmission station, Huts 3, 6 and 8 were constructed to be used as locations to break the code generated by the German Enigma machine. Huts 6 and 8 were connected by a tunnel through which encoded messages were delivered on a tea cart. Each of the huts were dedicated to a different section of the German military such as the SS, U-boat transmissions, Air Force, Naval and etc. all communicating with the Enigma code. It was the task of these units to break their code and reveal the messages. (Monckton, 295)
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The German Enigma Machine The Enigma machine was used by the German military to produce encoded and ultimately decode messages. In order to decode these messages, each Enigma machine had to be configured to use the same key that the messages had been encoded with. To make it even more difficult to intercept and decode, the Germans used a different key each day. The possible number of keys that the Enigma could produce was 3x10114 which would make it virtually impossible for enemy decoders to anticipate they key that had been used for any given day. Fortunately for the British staff at Bletchley Park, the Germans did not take full advantage of the Enigma machine. A number of decisions were made by the Germans which drastically reduced the number of combinations used to produce the key to 1023; still a daunting task for the codebreakers at Bletchley Park. (Kozdron) Panzer General with Enigma; This image features a German general in what looks like a communications truck at rest. (Image 2)
Due to success of the Enigma machine, Britain found itself losing the war. It was believed that the code produced by Enigma was just too difficult to crack. Only two men at Bletchley Park, Frank Birch and Alan Turning, felt that the code was breakable. Birch thought it could be broken because it had to be broken and Turing thought it could be broken because it would be so interesting to break it. Whether or not these reasons Alan Turing (Image 3) Frank Birch (Image 4) were logically satisfactory they imbued those who held them with a determination that the problem should be solved and it is to the determination and force that, in utterly different ways, both of them showed that success was ultimately due. [1]
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The Bombe Up until Turing’s arrival at Bletchley Park in 1939 no one had made an attempt to break the Enigma code. Because the key to the encoded messages were changing daily, Turing new that it would be impossible to correctly calculate the key using purely human efforts. This task needed a machine; a machine that Turing had theorized to serve as an idealized model for mathematical calculations. [2] The realization of Turing’s theory was a more sophisticated model of his design called the Bombe. It was
The Bombe of Bletchley Park, 1943 (Image 5)
not until after the war had begun, in October 1939, that development of the Bombe began and it was in May 1940 that the first prototype Bombe machine was delivered to Bletchley Park. [3] Unfortunately the Bombe was an expensive apparatus and it was far from certain that it would work or, even if the Bombe itself worked, that it would enable Britian to break Enigma. Its original production, and above all the acceptance of a scheme for large scale production, was the subject of long and bitter battles. [4] However, the escalation
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of the war necessitated that Enigma be broken and a mechanical solution to the problem was the only answer. (Smith, 208) The arrival of a mechanical solution to determine the key of the Enigma machine sped up the process of the codebreakers and in January of 1941, a year and a half after work began on the Bombe, British intelligence was able to crack the first encoded message intercepted from the Germans.
Colossus Even though the German High Command was unaware of British Intelligence’s ability to crack the Enigma code at Bletchley Park, in 1942 the Germans upgraded their Enigma machine. The new machine, known to the Germans as the Lorenz but at Bletchley Park as Tunny, altered some of the components and introduced the ability to generate more keys for encoding by a factor of 2662. Messages sent using Tunny concealed the highest grade of communications from German military intelligence. The increased security provided meant that the existing Bombe machines, while not redundant, would take considerably longer to complete a run, as much as 150 days of Bombe time. At that time the GC&CS was running 12 Bombe machines; this meant that even if all 12 machines were set to solving just one day’s settings, using the new system, it could take at least two weeks to make a successful run. [5] A bit of luck such as obtaining a Tunny machine from a German U-boat, and transmission protocol lapses helped, but to crack the messages between members of the German High Command, something new was needed. And that something new
Wrens (members of the Women’s Royal Naval Service) at Bletchley with Colossus, the world’s first electronic programmable computer, in 1942. (Image 6)
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was the world's first computer - Colossus. (Keir) Colossus was the brainchild of Thomas H. Flowers. Flowers joined the staff at Bletchley Park to assist Turing in cracking the Enigma code but soon became involved working with Tunny. Joining Flowers at Bletchley Park was Max Newman a former professor of Turing who oversaw the work with Tunny. [6] The prototype for Colossus was brought to Bletchley Park in trucks and reassembled by Flowers’ engineers. It had approximately 1600 electronic valves and operated at 5000 characters per second. In December of 1943 the first Colossus computer went to work, attacked its first message on February 5, 1944 and immediately doubled the codebreaker’s output. [7] The work at Bletchley Park could not have been any timelier as the number of troops the German military had at its disposal peaked the same year Colossus began calculating key settings for Tunny. The Allied Forces were mounting a major military offensive against Germany and the codebreakers at Bletchley Park were staged to play a critical role in the invasion of Normandy. Hut 3 was the Allied Troops using intelligence intercepted at Bletchley Park section of Bletchley Park invade the shores of Normandy. (Image 7) responsible for translating, interpreting and then distributing deciphered messages sent by the German army and Luftwaffe using the Enigma machine. One of the earliest intercepted messages, picked up on the night before the invasion, was a German report of parachutists landing behind German lines in Normandy, as the first of 24,000 paratroopers were dropped into occupied France. In the early hours, the Germans reported fierce fighting, but remained apparently unaware of the vast Allied armada approaching. [8] The messages intercepted and decoded at Bletchley Park proved vital to the deployment of Allied forces on D-Day. From these messages, Allied commanders knew how the Germans were positioning their forces and were able to adjust accordingly. In addition, these messages let Allied commanders know that the German High Command was oblivious to their intent and allowed them to proceed with their plan with confidence and the element of surprise.
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Hut 3 at Bletchley Park, Buckinghamshire in 1942. Here, civilian and service personnel worked together at code-breaking top-secret military communication between Hitler and his armed forces. (Image 8)
Post-War The intelligence gathered by the codebreakers was the most closely guarded secret of the war. Even though 20,000 people knew of the work, the truth did not emerge until the 1974. Most of the Colossus machinery was broken up after the war to preserve secrecy, but the science discovered at Bletchley evolved at tremendous speed. The work of Turing, Flowers and the other Bletchley Park scientists now touches every aspect of life. [9] Despite its significance Bletchley Park almost faded from memory. In 1991, the site was almost empty and plans were made to demolish the buildings for a housing development. In May of that same year the Bletchley Archaeological and Historical Society brought together former codebreakers for a farewell before the site was destroyed, but it was agreed that they would attempt to save the site for posterity. Through a series of grants to the Bletchley Park Trust, which took the Park over in 1992, the site was given a much needed restoration and is now home to the National Museum of Computing. [10]
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Designed by to break Enigma code, this fully-operational rebuild is on display at Bletchley Park
In September of 2009, over 115 World War II veterans accompanied by friends and family returned to Bletchley Park for an Enigma Reunion, which celebrated the 70th anniversary of the arrival of the original codebreakers in 1939. During the day, veterans were given demonstrations of the Bombe and Colossus machines, on which many of them worked. [11] Due to a grant provided by Google, exhibits in the museum are available online through the Google Cultural Institute. The digital exhibit features material from Bletchley Park's Archives, providing a vivid snapshot of the work of these men and women that went on decoding secret messages and the role it played in shortening the war. [12]
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Footnotes [1] C.H.O’D. Alexander, Cryptographic history of work on the German Naval Enigma (no date, c.1945), HW 25/1, The National Archives, Kew (TNA). This document was accessed online courtesy of Graham Ellsbury, http://www.ellsbury.com/gne/gne-000. htm (Retrieved Mar 29, 2015). [2] Weisstein, Eric W. "Turing Machine." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/TuringMachine.html (Retrieved Mar 31, 2015) [3] Birch, The Official History of Sigint, vol. 1 (part 1), 41. [4] Mahon, The History of Hut Eight 1939 – 1945, HW 25/2, TNA. 28. [5] Smith, C. (2014). How I learned to stop worrying and love the Bombe: Machine Research and Development and Bletchley Park. History Of Science. 211. [6] Copeland, Jack, Colossus: The First Large Scale Electronic Computer. http://www. colossus-computer.com/colossus1.html . (Retrieved Apr, 3 2015) [7] Copeland, B. J. (2006). Colossus : The Secrets of Bletchley Park's Codebreaking Computers. Oxford: Oxford University Press. 75. [8] Ben, M. (2014). Chaos of Germans intercepted by Bletchley. Times, The (United Kingdom), 9. [9] Ben, M. (2013). FROM BLETCHLEY PARK TO THE NSA. Times, The (United Kingdom), 9. [10] Bletchley Park Science and Innovation Centre. http://www.bpsic.com/history-ofbletchley-park. (Retrieved Apr 4, 2015) [11] Record Number Of Bletchley Park Veterans Attend 70th Anniversary Celebrations. (2009). M2PressWIRE [12] Weiss, T. R. (2014). World War II Codebreaking Center Is Reborn After Being in Disrepair. Eweek, 10.
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References Keir, D. (n.d). Codebreakers central Now a shabby bolthole, the wartime work done at Bletchley Park in the UK saved thousands of lives.Townsville Bulletin. Kozdron, Michael. (2006) The Theoretically Possible Number of Enigma Configurations. (Retrieved Apr 3, 2015.) Monckton, L. (2006). Bletchley Park, Buckinghamshire: the architecture of the Government Code and Cypher School. Post-Medieval Archaeology, 40(2), 291-300. doi:10.1179/174581306X160080 Smith, C. (2014). How I learned to stop worrying and love the Bombe: Machine Research and Development and Bletchley Park. History Of Science, 52(2), 200-222. doi:10.1177/0073275314529861
Images Cover Image: The Station X at Bletchley Park, Buckinghamshire, Enland http://www.gchq.gov.uk/history/Pages/index.aspx) Image 1: http://www.dailymail.co.uk/femail/article-1308445/Romances-night-shift-nervous-breakdowns-The-secret-life-Bletchley-Park.html Image 2: http://www.ilord.com/vintage.html Image 3: http://www.matematiksider.dk/enigma_eng.html Image 4: http://spartacus-educational.com/Frank_Birch.htm Image 5: http://www.computermuseum.li/Testpage/Bombe-1943.htm Image 6: http://www.bbc.co.uk/history/places/bletchley_park Image 7: https://vulgarmorality.wordpress.com/2010/01/ Image 8: http://www.bbc.co.uk/history/code_breaking/
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