The contribution of intelligence obtained through code breaking in World War II cannot be easily overstated. Considered amongst the most carefully guarded secrets and known only by its codename “Ultra”, allied intelligence derived from tapping encrypted communication of the armed forces of Germany, Italy, and Japan changed the course of the war.
It significantly contributed to the Allied victory in WW2. But, for all the legends that surround Ultra intelligence there is a far larger story to tell than solely that of the brilliance of the codebreakers at Bletchley Park. How did they do it?
Bletchley Park and Ultra
At Bletchley Park, a large country house near to London taken over by the British wartime government, a group of code-breakers created techniques to decrypt the coded messages of the German operators using of electrical cipher machines. This military intelligence developed by Bletchley Park was known by the code name “Ultra” and every effort was made to disguise the source of the information.
Even Ultra itself had its own cover name to obscure its origin, being referred to as “Boniface” when directly linked to signals intelligence or the codebreaking site itself. Most of the sources of Ultra intelligence were the radio messages that had been encrypted with cipher machines, primarily the German Enigma machine.
During World War II, the German military used to transmit thousands of coded messages on a daily basis. Starting from the situational reports by the front line generals to the different orders signed by Adolf Hitler, various coded messages were transmitted.
Many of these messages ended up in the hands of the Allies, but there was certainly some luck involved. The German military Enigma was virtually unbreakable when used properly. However, the lack of proper operations resulted in the breaking of the Enigma codes.
For example, messages would be repeated letter for letter which allowed a comparison between two different coded transmissions with the same hidden message. German Enigma operators running tests would sometimes transmit the same letter over and over again, allowing the codebreakers to isolate the workings of the machine itself.
There were other breakthroughs which helped also, such as Poland obtaining an early enigma machine before the Second World War, and the capture of a German naval enigma machine in 1941. Having an intact machine was invaluable to understanding how it encoded messages.
None of these would have been a success without raw computing power, and with machines such as Colossus numbers were crunched at an unprecedented rate. In using mathematicians in concert with these machines, the Allies were able to decipher intelligence thought unbreakable.
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Ingeniously, the Axis transmissions could also be analyzed without even understanding what they said. The messages themselves might be unreadable but the Allies could track where they were sent and by whom, allowing them to build up a detailed understanding of German military organization without ever reading them.
This proved invaluable both in monitoring German movements, and even helped in breaking the code as Bletchley Park could now guess at what was being said due to the context of the message. By the end of the war the Allies understood the German chain of command almost as well as the Germans did.
Information provided by Ultra
A lot of information was provided by Ultra intelligence to the Allies, right from the start of the war. Such information contributed significantly to their success. As early as April 1940, information gained through Ultra intelligence offered a detailed picture of the disposition of the German forces.
It also provided information relating to the movement orders of the German forces for the attack on the Low Countries before the Battle of France in May of that year. In June 1940, an Ultra decrypt provided the Allies with information relating to the development of a radio guidance system for the bombers.
During the Battle of Britain, Ultra intelligence was used in order to provide information relating to the strategies adopted by the German forces. It provided information about the location and strength of different Luftwaffe units. Moreover, it also provided the Allies with advance warnings of the bombing raids.
Combined with the advance warning offered by the new radar stations on the south coast of England, the Royal Air Force became so successful in anticipating German attacks that the Germans became suspicious. Britain’s answer was both audacious and hilarious: a fake advertising campaign was started to encourage people to eat carrots to see in the dark, stating that this was what the aircrews did to better see and intercept German night-time attacks.
Through the decryption of traffic coming from the Luftwaffe radio networks, the Allies were able to learn a lot relating to the planned Operation Sea Lion: Hitler’s plan to invade England. On the 17th of September, 1940, the Ultra message provided the Allies with the information that the equipment at Belgium’s German airfield, the loading planes, along with their gears and paratroops, were to be dismantled. This helped the Allies understand that Operation Sea Lion was canceled.
Ultra also helped in revealing the information that a major air raid was planned by the German forces on the night of the 14th of November, 1940. There were mainly three targets of the air raid, which included Coventry and London. However, the particular target could not be determined until late afternoon. Coventry was not warned and in a single night the center of the city was destroyed.
Ultra intelligence has significantly helped the British Army in order to gain victory over the larger Italian army from December 1940 to February 1941 in Libya. Ultra intelligence allowed the Allies to learn about the preparation for Operation Barbarossa, Germany’s fatal invasion of the USSR.
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However this intelligence ran into another problem: ego. While the information was passed on to the Soviet government, Stalin refused to believe it. The information obtained through Ultra intelligence allowed the British to plan effectively as they already had the knowledge about the deployment of the German forces to the East, but the Soviet lack of preparedness allowed Hitler to march almost within sight of Moscow.
Ultra intelligence played perhaps its most important role in the Battle of the Atlantic. Decrypting the Enigma signals to U-boats was very challenging in comparison to the Luftwaffe but from June 1941 Bletchley Park was able to read at least some information. If the Germans could be tracked in the Atlantic they could be avoided too, allowing vital supplies to reach the United Kingdom and keep Britain in the war.
Of The Highest Importance
While Ultra Intelligence provided valuable information to the Allies, there was always a risk that the German government and military would find out about the operation. This would result in the changing of the encryption devices by the German military, and the Allies would once again be blind.
Therefore, Ultra operated in a very secure manner. In order to ensure optimum security of the operation, the details of Ultra intelligence were only known by four people.
Moreover, for the dissemination of the information of Ultra intelligence, the usual intelligence protocols were not followed. Instead, unique communication channels were used. The intercepts were provided to the Ultra liaisons by the military intelligence officers. The liaisons forwarded the intercepts to the Bletchley Park, providing a cut-out between the intelligence and those who used it. Almost all of the people who acted on Ultra intelligence had no idea where it came from.
And the use of information from Ultra intelligence had a great impact on the war. However, the exact influence of Ultra intelligence on Ultra intelligence has been a topic of debate. There exist disagreements relating to the importance of code breaking and the winning of the important Battle of the Atlantic.
On the other hand, there are people who believe that Ultra intelligence shortened the war by as much as three months. It helped the Allies to win against the German forces effectively, saving countless Allied lives.
In modern British history, the British code-breaking efforts made during the war are one of the most celebrated aspects. Moreover, it has also evolved as a popular story that depicts how intellectual resources were properly used by the Allies against the German military. Without Ultra, the war could have ended very differently.
Top Image: D Block at Bletchley Park: from these nondescript buildings came the intelligence which helped win the war. Source: Barrymyles / CC BY-SA 4.0.
By Bipin Dimri
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