The story of the German cipher machine Enigma received a lot of publicity and became widely known after the movie U-571 was released. The story showed how brave American soldiers captured a German U boat with a valuable machine on board and, thanks to their effort, the Allies were able to decipher secret German codes.
Unfortunately, the story is pure fiction, exactly the same as another one, showed in the movie „Enigma”, directed by M. Apted
The original Enigma device was developed by a German engineer named Arthur Scherbius and was patented in 1918 during the World War I. It was a commercial device available by mail order to anyone who wanted to buy it. Although Scherbius and his partner E. Richard Ritter approached the German government, no secret agency showed interest in their machine. During the following years, several improvements were implemented and Enigma became well known in Europe, Asia and United States, being legally sold in many countries.
Italy was the first country who tried to use it for military purposes, then several others followed, including countries like fascist Spain (under the leadership of General Franco) and even Switzerland.
Most of the codes were broken, but German officials grew more interested in military use of Enigma, with 4 rotors at that moment. At one point it was believed that Enigma would assure secrecy of orders to armed forces. The Polish Cypher Bureau BS4, by German mistake, intercepted a parcel with fully working Enigma machine and had an opportunity to analyse and investigate it before returning it to Germans.
In 1932, the German Army ordered the creation of 3 Enigmas and within 2 years improved them and designated them as Enigma I, which was used in WWII. Finally, both the German Navy and Air Force adopted Enigmas for their use.
What Germans did not know is that Polish Intelligence had a machine that could decipher the secret messages. Hans-Thilo Schmidt spying for France in ’30 was delivering vital intelligence information, including Enigmas’ user manual. Thanks to documents he provided, the Polish mathematician Marian Rejewski designed a machine called “The Cryptological Bomb,” allowing the operator to read the message. As the Germans were improving the design and updating the complexity of Enigma, Poles were not far behind. Rejewski designed and built a code-breaking machine known as the “Bombe.” This machine allowed Polish Intelligence to read top secret German messages, including German plans to cross the strip of land leading to the free city of Danzig. When Polish Intelligence realized that war was inevitable, it was decided to share the secret with the Allied countries of France and Great Britain, delivering them all the code-breaking documentations and equipment the Poles had.
Even the British admit that without Polish help, the probability of breaking the Enigma’s code was very low; some even have said it would have been impossible.
A month before war started, in August 1939, the British Government Code and Cypher School was moved to a mansion in Bedfordshire, the Bletchley Park. The man who was meant to decide what to do with the information from Poles was a young genius mathematician, Alan Turing, who is frequently credited as a founding father of modern computer science.
Turing upgraded and improved the old design, creating his own Bombe, which was installed in Bletchley Park in March 1940. It was a size of a large book-case, and after setting up separate decoding stations, the British were able to decode military German transmissions. Everything was top secret, and even years after the war ended, the personnel kept everything in secrecy.
Two years later, the documentation of Enigma was passed to Americans; the same year, in December 1942, Alan Turing was seconded to Washington. A few months later, Americans had their own devices capable of decoding messages deemed impossible to break.
Project Ultra was a code name for top secret operation that was originated in Bletchley Park. Teams involved in that project were monitoring and decoding transmissions from Kriegsmarine High Command to U Boats as well as decoding orders being sent to Nazi units in Africa in 1941. This shed new light on the North Africa campaign as the Allies knew German plans in advance and were prepared for Rommel’s actions. The most valuable bits of information were decoded before the D-Day. The Allies knew details and locations of 56 out of 58 German Divisions on Western Front before landing in Normandy. All of this information was shared with Americans who were even invited to visit Bletchley Park, but as Churchill never trusted Stalin, the Soviets were never informed of its existence.
At one point, there were over 9000 personnel working at Bletcheley Park.
Ultra was one of the main factors that allowed the Allies to win the war. Enigmas were the Ultras’ main target – but it was not the only target; Ultras were being used to decode messages from other encrypting devices. Both Churchill and Eisenhower have said that the Ultra was crucial to winning the war.
While credit is given to Alan Turing and the brilliant code-breakers at Bletchley Park, there were also other unsung heroes. Polish mathematicians, led by M. Rejewski, broke the Enigma code first and shared their secrets with the Allies. If it was not for them, World War II could have ended completely different and Germans may have even won.
Featured Image – Four Rotor Enigma. Author: Greg Goebel. Public Domain.