*** World War II -- Allied code breaking, lack of detection

World War II: Allied Code Breaking -- Lack of Detection

Figure 1.--The basic Enigma was complicated enough. Other features such as the plugboard further complicated it. Changing the position of the interchangeable rotors was another complication. And a suspicious Adm. D�nitz insisted on adding a fourth rotor to the Naval Enigma. The incredible mathematics involved convinced most Germans that Enigma could not becracked.

An interesting question that needs to be considered is why did neither the Germans or Japanese detect that their codes had been broken. This is not to say that there were not suspicions, but apparently neither of the two main Axis powers was convinced that the Allies had cracked their codes. Some of the reasons are the same for both the Germans and Japanese, but other reasons are unique. Their is no one single definitive answer to this, but we have some ideas here and would be interested in ideas that readers may have.

The Germans


First of all, at least the Germans began to realize in the final year of the War that their codes had been broken. For the Germans, the question while a good one is a little off. Some Germans were suspicious (especially Doenitz but also Rommel), but the experts in Berlin assured them that it was impossible to crack Enigma. Doenitz was so suspicious that he added a fourth rotor to the Naval Enigma. And the Gestapo got their hands on one of the Polish Cryptologists who broke the pre-War Enigma. And note that in the lead up to the Bulge, the Germans stopped transmitting orders by wireless messages. In the East, the Soviets may not have cracked Enigma, they appear to gave cracked lower level codes. We do not have a lot of detail here because the Russians have only minimally opened their World War II files.

Failure to detect

It is true, however, that the Germans were not convinced their codes were broken and used Enigma throughout the War. Only with the Bulge did the Germans stay off Enigma. So the question is a good one. The answers here cover most of the reasons, although though they mostly discuss how Enigma was cracked, not why the Germans did not realize it had been cracked. Colin Povey provides an especially good answer. Our take is:

1.) The Germans bought into the myth that they were superior to everyone else. Even at the end of the War, with German cities turned into mounds of rubble, German officers still believed they were superior, just overwhelmed by inferior but larger forces. As they couldn't conveive of cracking Enigma, they assumed that the Allies could not do it.

2.) So it is not hard to understand why the Whermacht had so much faith in Enigma. The numbers certainly seemed daunting. The possible numerical possibilities that Enigma could generate certainly seemed like it was impossible to crack. The number of possible settings varies with the type of Enigma (the Naval enigma had a fourth rotor) and how the machine was set up. But basically there could be potentially something like 160 quintillion possible settings for a single letter. We have seen various estimates, but this is a ball park figure indicating the unimaginable possible computations and what the Blechly code breakers were faced with. It just seemed beyond human caspabilities to crack Enigma, especially to decrypt Enigma messages in a timely manner.

3.) All the early German successes gave no evidence that Enigma had been cracked. An army winning great victories is just not that interested in codes and code breaking. As it was, cracking codes is much more useful to a military on the defensive than on the offensive.

4.) Even at the time of Barbarossa, the Germans were able to catch their victims unprepared. In this case both the British and Americans learned of Barbarossa through Ultra and Magic, and informed Stalin. Informing Stalin Only Stalin in his convoluted mind was convinced it was just Allied disinformation to create a rift with Hitler and dismissed the warnings. He was sure Hitler would not strike until the British had been defeated in the West. Hitler had repeatedly said that a two front war was the Kaiser�s great mistake in World War I.

5.) B-Dienst success in cracking the British Naval codes gave the Germans further confidence in their infallibility. (Interestingly the British were very concerned about their new American ally leaking the Ultra secret when it was they who had their codes cracked.) Fortunately, the German decrypts of the Royal Navy codes contained no evidence of Ultra.

6.) The British were careful to provide alternative explanations whenever forces acted on Ultra decrypts. One of the greatest uses of Ultra was going after the Italian convoys supplying the Afrika Korps. In thiscasethey hadcrckedthe Italian codes. But the British made a real effort to stage air or naval sightings before actual attacks.

7.) Perhaps most importantly, there was no smoking gun. Ultra was tremendously useful to the Allies, but unlike the Pacific there was no major action in which victory could be obviously ascribed to Ultra. And there was not a single battle in which Ultra played a decisive role. It was useful in many, but nothing like Midway in the Pacific. A factor here is that most of the major battles of the War were fought in the East (Soviet Union).

8.) The great bulk of the German War was conducted in the East. Something like 90 percent of the German casualties were sustained in the East andmost oftheWhermcht wasdeployedthere--some 300 divisions. Barbarossa Large numbers of Enigma machines were used in the East and the Soviets must have captured some and the code books as a result of their many offenses. And the Soviets did not have Ultra, although they apparently were deciphering some German messages�although not in real time like the Allies. The Allies beginning with Barbarossa provided the Soviets information derived from Ultra, but never actual decrypts which would have given away the Ultra secret. They also didn't tell the Soviets they had cracked Enigma. (They did not need to. The Soviets had penetrated MI-6 and thus knew about Ultra.) The Soviets must have gotten their hands on many Enigma machines and code books. They surely must have tried to decipher Enigma. We have, however, been unable to find much information on Soviet code breaking operations. They do seem to have made some progress. World War II -- Soviet code breaking Unlike the Allies who have declassified most World War II archives, Soviet archives contain a vast quantity of documents that the Russians refuse to make available to historians. They began to allow Western historians to look at the Soviet archives after the dissolution of the Soviet Union, but Putin shut that down.

The Japanese


As for the Japanese, they were also suspicions, but it is much more difficult to understand why the Japanese did not realize their codes had been cracked. Some of the same reasons the Germans did not realize apply to the Japanese as well. Unlike the Germans, however, there were very clear smoking guns in the Pacific that the Japanese should have easily picked up on.

Failure to detect

Here are the probable reasons that the Japanese failed to realize their codes were cracked.

1.) Before Pearl Harbor, the Germans learned about Magic. Actually the Soviets learned about it and informed the Germans who at the time were allies (to both the Soviets and Japanese). Now we do not know for a fact whether the Germans passed the information on to the Japanese and or just who they informed, but it is difficult to believe that they did not inform their Japanese friends. The most likely scenario is that the Japanese were told and arrogantly dismissed the report. https://www.histclo.com/essay/wa...

2.) The Americans had broken Japanese World War I codes and the code breakers went public after the War. The chief American code breaker wrote a tell all book��The Black Chamber�. The Japanese as a result knew about what happened in detail. They thus had every reason to expect that the Americans: 1) not only would be working on their codes, but 2) were highly competent at code breaking. World War II -- country code breaking America United States

3.) The numbers of alternatives generated by the Japanese code machines like Enigma were daunting. It seemed impossible to the military that they could be cracked.

4.) The Japanese like the Germans thought they were superior to the bumbling and decadent Americans. Actually there was considerable truth in this at the onset of the War. The Japanese achieved an impressive string of stunning victories, at least for 6 months months until the Arsenal of Democracy kicked in and America shifted over from peace to war making. The problem for the Japanese was during those 6 months of victories, rather than convincing the Americans to make peace they converted a country wanting peace and building refrigerators into a country committed to using its massive peacetime industrial capacity into a fearsome war-making engine.

5.) The Japanese assumed that the complexities of their language was a kind of coding defense in itself. Unlike German, the number of Americans who spoke Japanese was minuscule.

6.) The Japanese went to the Germans for technological assistance. The Germans were not disposed to provide much until the War began to go against them. As far as I know, the Japanese never added code making and breaking to their requested technology. This probably reflected security concerns toward the Germans and their own priorities. They just did not believe they had a security problem.

7.) Victory Disease (a Japanese term) affected not only military operations, but the Japanese attitude that they were a superior people and not only in military matters to the Allies and this included attitudes toward codes.

8.) Actually at Midway, the Japanese First Air Fleet was operationally superior to the Americans with superior carrier operations and more capable pilots, torpedoes, and aircraft. Notice how easily the Japanese found the Americans once they were discovered and how much trouble the Americans had finding the Japanese. The difference at Midway was that the dismissive Japanese attitude toward towards American capabilities and their broken codes. The Chicago Tribune after Midway published articles that made it clear that JN-25 had been cracked. But it is perhaps understandable that there were no Japanese spies in Chicago.

9.) Confidence in their codes were so absolute that the Japanese had their marus signal their position daily. Which of course was very helpful to the American submarines searching for them. The Japanese did not seem to wonder why their marus were constantly being found and sunk in the vast stretches of the Pacific.

10.) The Japanese understood that America was the world's leading industrial power, some of the militarists more than others. But they believed that Japanese fighting spirit would overcome industry and material advantage. Not only was America�s industry much larger than Japanese industry, but also all the other related attributes of an industrial society such as technological institutes and universities.

11.) Even with all of these disadvantages, the Japanese militarists who launched the War believed America could be overcome by the fighting spirit of the Japanese soldier which indeed was impressive. They were thinking about war production. There one pre-War experience with a modern army (the Soviet Red Army) was a disaster (July 1939). This should have told them that fighting spirit only went so far. And they failed to realize that code-breaking ability was one of the skills available to to an industrialized nation. This was one of the many factors the Japanese did not think through.

12.) The Japanese made absolutely no progress in cracking American codes. The conclusion they took from that was that modern codes could not be broken. They did not believe that the Americans could do something that they could not. And the string of victories after Pear Harbor just confirmed Japanese belief in their superiority. This was especially true of codes as if their codes were broken they could not have carried off so many successes.

13.) Even after the Japanese surrendered, the Americans allowed them to continue sending coded messages because they were all being decrypted. Here Victory Disease was a mjor factor. This allowed the Americans to see if the Japanese were complying with American surrender instructions.

Difference: Smoking Guns

Now the difference between Japan and Germany is that there was a smoking gun in the Pacific. In fact two: Coral Sea and Midway. The Pacific is a vast ocean, by far the largest ocean. And yet the U.S. Navy (specifically the American carriers), with its limited resources in 1942, showed up at just the right TIME and PLACE to oppose the vastly superior Imperial Navy. And despite these obvious smoking guns, the Japanese did not pick up on the obvious fact that their codes had been broken.

1.) Coral Sea: The idea that American carriers would show up in the vast Pacific just right at the TIME and PLACE that the Japanese were staging a major military action defy any explanation except that their codes had been broken. It was not just a chance sighting by some nondescript Allied vessel. It was the major striking force of the U.S. Navy. This was especially the case because by all military logic, the American carriers should have been at Pearl Harbor defending the principal United States asset in the Pacific, not in the remote South Pacific Coral Sea. The Japanese seemed to have dismissed code breaking in part partly because they saw the battle as a great victory. They believed both Lexington>/i>� and Yorktown had been sunk and their two fleet carriers, Zuikaku and Shokaku, had survived. And they were the Third Division, the newest carriers with the least experienced air squadrons.

2.) Midway: Now one might dismiss Coral Sea as mere chance, though not very easily, but it was not totally impossible. After all, they saw Coral Sea as a substantial victory, confirming their belief that the American carriers were a sub-standard force. (Actually there was some truth to that at the time.) The idea that the American carriers should show up only a month later, again at precisely the same TIME and PLACE where the Japanese were striking defies even the most basic military thinking. Chance was theoretically possible once, but twice? And they showed up at the perfect place to take on the carriers, not just some unit of the cast Japanese fleet�but specifically the First Air Fleet. And yet the Japanese convinced themselves that the bumbling Americans by mere chance had gained a great victory. As a result, even after Midway, the Japanese did not think that their their codes had been broken.

3.) Other smoking guns: There were other smoking guns like the Yamamoto shoot down and the American subs so easily finding their marus in the vast Pacific. The Japanese continued to think that their codes were secure throughout the War and for that matter after the War.


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Created: 12:47 PM 2/10/2019
Last updated: 12:47 PM 2/10/2019