The Machine that Lost World War II for the Germans
|Very Rare WWII Enigma Cipher Machine. This highly important three-rotor Enigma deciphering machine was used by the Germans during World War II. Examples of Enigma machines are exceptionally rare and almost all known models are in museums.|
Wireless transmissions were critical to the Wehrmacht's "Blitzkrieg" operations. These relied on close communication between ground and air units, with ground-attack planes hitting targets requested by the ground troops. While telephones were used for official communications within Germany, radios were used outside the borders. Those communications had to be encoded, and the Enigma machine was the tool of choice.
|Italian Naval crypto officers operating an Enigma machine, not knowing that the cipher was being read by the Allies|
Enigma Machine Use By The GermansThe use of the Enigma machine was not a Third Reich idea. In fact, it was advertised for commercial use in catalogs beginning in 1923 to anyone willing to pay for it. The German military had adopted the machine well before Hitler took power in 1933, with the German Navy being the first to use it in 1926. The military modified the Enigma machine to include a plugboard and other enhancements to make it more secure.
The Poles, Germany's natural enemy during the inter-war period, became interested in this new machine also. The first Enigma machine in Allied hands was ‘acquired’ by Polish intelligence in 1938 by setting up a fake German arms company and ordering a civilian version. The Poles went to work on it at once and first broke the German military code in 1932.
On 15 September 1938, the Germans changed their use of the Enigma cipher, implementing a new key scheme as the war drew nearer. The new code appeared vastly more complicated, so the Polish cryptologists invented the first mechanical pseudo-computers to help them in their work. In October 1938, Rejewski designed a machine named "bomba kryptologiczna" (a cryptologic bomb, as computers were known in those days), which was soon produced at the Polish AVA Workshops. They also developed a "cyclometer" machine to assess the pattern of the key.
|Close-up of a later Enigma machine. Note the fourth "shark key" rotor.|
The Polish cryptographers had to leave Poland in a hurry that autumn, and after a quick stop in Romania they wound up in France. There, they worked with French and Spanish cryptographers under code-name "Bruno." They also continued to keep the British up to speed on their cryptological discoveries. After Germany invaded France in May 1940, the Poles again evacuated. This time they went to Algeria, using a French military plane on June 24, 1940, in one of the French government's final acts before their Armistice with Germany. After working in Algeria for a while, the Poles returned to France and worked right under the Germans' noses in Free France.
At the beginning of October 1940, the Poles set up shop in Fouzes, France under code-name "Cadix." They worked there with French and Spanish cryptographers. The "Bruno" center successor decrypted the following types of German messages:
- German military orders to the units in Europe and in Libya,For those who claim that breaking the Enigma Code was all things to all people, note that although the Poles broke the code first, there is absolutely no indication that they were able to use that information to any great advantage. In fact, the results of breaking the German code appear to have been fairly valueless to Poland. Knowing what the enemy is saying only helps if you know how to use the information to your advantage, get the right information from the enemy to help yourself, and have the resources to make good use of it. For all the brilliance displayed in cracking the code, none of that appeared to apply to Poland and its cryptographers.
- SS and Police (Polizei) messages from Europe,
- Spy radio communications between the field agents in Europe or in Libya and Abwehr HQ in Stuttgart,
- Diplomatic communications and German Armistice Commission communications
- Communications by Wehrkreis XII (controlled parts of occupied France and western Germany) in Wiesbaden and their branches in France and in North Africa.
|Not all Enigma machines looked like they - they were built over many years with different models and styles. This is one in use in 1943.|
|A crew aboard U-110 operates the iconic Enigma machine, so valuable to the war effort at sea.|
The Polares IncidentOn 24 April 1940, two British destroyers, HMS Griffin and Acheron, were on patrol in the North Sea when they stopped a merchant ship for inspection off Andalsnes, about halfway between Bergen and Trondheim on the Norwegian coastline. The ship's captain claimed that it was an ordinary Dutch trawler. The British boarding party from Griffin did a thorough inspection and found that it was the disguised Kriegsmarine surface raider Schiff 26 - the Polares. It was trying to bring supplies to Narvik.
The German crew acted quickly and threw a weighted bag overboard. The British acted even quicker and retrieved the bag before it sank. It turned out to contain some of the German Enigma machine coding machine keys for the period 23–26 April 1940, including the procedures for scrambling the rotors.
|The crew of HMS Griffin (H31), shown, was responsible for one of the biggest Ultra advances of World War II.|
This was a clear breakthrough for the Ultra team. Now, they had proven that their system works. From this point on, the Royal Navy is tasked with finding new "cribs" such as the ones from the Polares to enhance their code-breaking. Ultimately, this enabled the Bombes to break German codes routinely even without recent cribs.
The U-559 Incident
Two of the men perished in the U-board. The third man, NAAFI canteen assistant Tommy Brown, came out with the submarine's Enigma machine key setting sheets and other relevant documents. All three men received medals, two posthumously.
The information from U-559 helped the cryptanalysts at Bletchley Park to read the new 4-rotor U-boat Enigma machine. This proved to be a critical breakthrough in the Ultra program. After this, the Ultra team could read U-boat codes and direct convoys away from lurking submarines. This incident was the basis for the motion picture "U-571" (2000).
Routine DecryptionThe British came to see the Luftwaffe operators, members of the newest service who had no tradition of security, as the weak link in the entire operation. Some Luftwaffe coders would send virtually the same messages out every day at regular intervals, morning, noon and night, and if the code they used had changed, the British listening in could compare the messages they had broken with new, identical messages sent with the changed code. This made it relatively easy (not easy - relatively easy) to figure out the changes made to the code itself.
|Enigma Machine recovered from a sunk U-boat off the US coast in 2001. Recovering an actual Enigma machine from a wreck is like finding the Holy Grail for a diver. These can be carefully restored and look almost like they did the day the sub sank.|
Overall, though, by the end of the war, 10 percent of all German Enigma communications were decoded by the code-name "Ultra" team led by Alan Turing at Bletchley Park, in England, using the world’s first electromagnetic computers. However, that means that 90 percent of German communications were not decoded, so it's important not to completely overstate the importance of Enigma.
Still, much is made of the effect of breaking the Enigma Code on the outcome of the war. There is absolutely no question that it made things much, much easier for the Allies in many, many situations. Knowing where to position scarce defensive forces before an attack is an invaluable information, as is knowing where the enemy is weakest before launching your own attack. There are all sorts of anecdotes about specific instances where breaking Enigma gave the Allies an edge. Winston Churchill told King George VI after World War II that "It was thanks to Ultra that we won the war."
|The rear of a 'bombe' code-breaking machine at Bletchley Park, 1943. Alan Turing designed the electromagnetic machines to reveal the plugboard settings on German Enigma ciphers.|
|German General Heinz Guderian in an SdKfz. 251/3 half-track vehicle, France, May 1940; note Enigma machine (German Federal Archive)|
|German soldiers in Russia using an Enigma machine (Federal Archive).|