** war and social upheaval: World War II -- country code systems








World War II: Country Secret Codes


Figure 1.--The great secret of World War II was the German enigma machine. The mobile mechanized operations in land, sea, and air required millions of message, all available in the air. The German Einsatgruppen even reported on killing operations in the East. Never before in the history of warfare has so much information been available on enemy operations. This was the case for both the Axis and Allies. The great prize was Germam Enigma machine because it was the Germans who were the great threat with German forces at the Channel, only few Miles from Suez, beseiging vital Soviet cities, and reaching the Volga--the proverbial Barbarians at the Gate (a Roman expression). Here we see an Enigma machine during World War II on a German railway car. Japan was just not the existential threat the Germans were. Cracking Enigma was a critical part of the Allied victory and the Germans neverlerned of it--although important German commanders, especually Admiral Dönitz was suspicious. The Germans were so proud of Enigma that they just could not believe it had been cracked. Noticed the three men here--ot took thee to operate an Enigma machine.

The major beligerant powers of World War II developed various encrytion systems. Those systems and the cracking of them played important roles in the War. Wireless radio communication was critical for directing military forces often spread at great distances and moving rapidly, spread all over the world. But radio messages were not secure and could be intercepted. Thus important messages had to be sent in code. All the major powers developed complex machines that could rapidly convert typed text into code and then on the other end back into code. Early histories of the War were written without benefit of information on these systems and code breaking efforts. The Germans thought that they had solved the problem and that theie Enigma Machine could not be cracked. They proved to be wrong. The British cracked it the Ultra program provided timely information on Wehrmacht activities. The most secure system proved to be the American SIGABA system. Information on the code systems for the most part has now been declassified and the details are available to historians. There were major impacts on the North Africa campaign, the Battle of the Atlantic, and the early stages of the Pacific War. The only aspect of Woeld War II codes that is not available to historians are Soviet efforts at code breaking. The Soviets and now the Russians have been reluctant to open their archives to historians.

America

American military codes proved to be the most secure system used in Wotrld War II. The Germans broke some codes before the United States entered the War. But at this time, a new code system was being introduced which Axis cryptologusts were unable to crack. The new American codes were never broken. Some authors have used the term 'unbreakable', but there is in reality no unbreakable system, primarily because people are involved. The Enigna machines, for example, were broken because the Brutish obtained actual machines and operators used sloppy procedures. The American code system was known as SIGABA which has been described as the most secure cryptographic machine used by any World War II beligerant. The U.S. Army developed the SIGABA system before the War. SIGABA looks like an acronym, especially the SIG which looks like signals. But in fact does not stand for anything. It is purely a code word. Army cryptologists completed the desigs for the basic machine (1935). It was similar in somecrespects to the German Enigma machine, but the output was emensely more complex. The Army shared the design with the Navy. The Army and Navy after field tests both adopted SIGABA (1940). The system was fully opperational (August 1941), but not fully deployed until after America entered the War (Early-1942). The military had deployed more than 10,000 SIGABA machines around the world (1943). As far as we know, neither the Germans or Japanese managed to capture one, but this has to be confirmed. We do not know to what extent the Germnans and Japanese or for that matter the Soviets tried to crack SIGABA. Unlike Enigma, SIGABA was never cracked. The SIGABA machines were linked with British machines to let Presidents Roosevelt and Truman communicate securely with British Prime Minister Churchill. The Germans were able to listen in to trans-Atlantic phone conversatiions even though they were scrambled. SIGABA messages, however, were secure. The Americans and British shared many secrets. One exception was SIGABA. The SIGABA system was so effective that it continued to be used by the Americans for more than a decade after the War. It was finally replaced when a faster communication system was required (1959). An interesting development during the War was the use of Navajo code talkers in the Pacific. The Germans did break the State Department's black code as well as descrabled trans-Atlantic telephone conversations.

Britain

Britain during World War I had separate Army and Navy signals intelligence agencies, MI1b and NID25 (also known as Room 40). We have been unable to fund much information on the codes used by the British Army and Royal Navy during World War II. There is considerable historival doscussion of British coe breaking, but very little avout Britain's own codes. They were particularly poor and many were broken by the Germans years before the War. After World War I it was disclosed that German and Japanese codes had been broken which is wj=hy both coyntries adopted modern code systems. The British felt less urgency to do so. We have noted reference to '5 digit' and '4 digit' Royal Navy codes, but we have not yet found details on the actual codes. Perhaps British readers will know more. After the War Lord Curzon chaired the Cabinet's Secret Service Committee (1919). The Committe was concerned with achieving greater efficency in Government milirary and security spending a reducing costs. The Committee recommended a combined peace-time codebreaking agency should be created. The assignment was given to Hugh Sinclair who was at the time the Director of Naval Intelligence. Sinclair moved to combine NID25 and MI1b into the new unified organisation. It was a fairly small organization, about 25�30 officers and a comparable clerical support staff. The new organization became known as the Government Code and Cypher School (GCCS), chosen as a inocuois cover-name chosen by Victor Forbes at the Foreign Office. Alastair Denniston, who had been a NID25 officer, was appointed as the operational head. rganizationally it was placed undr the the Admiralty and situated at Watergate House, Adelphi in London. Its stated function for public consumption was "to advise as to the security of codes and cyphers used by all Government departments and to assist in their provision." There waas also a secret directive impoweing the new GCCS to to "study the methods of cypher communications used by foreign powers." GCCS officially began operating a year after the War (Nonember 1919). The GCCS was moved to thge Foreign Office (1922) and as a result it focus shifted from military to diplomatic codes. Only in the 1930s and the rise of the NAZIs and increasingy aggressiveness of the Japanese did the focus shift back to military signals. To deal with the increasuing demand and staff, the GCCS purchased a country estate where the work could be conducted in greater security--Beletchley Park (1938).

France

We have been unable to find much information on French World War II codes. We would be interested in any infomation reader may have. Of course the Germans defeated and occupied France in the firt year of the War (May-June 1940). This meant that two French code systems functiond during the War. There were Vichy codes and the Free French underground codes. Ininiat resistance to the German occupation was slight, but increased as the German occupation became increasingly explotice anbd s the Germans began to suffer significn military defeats, mostly in the East. The German secret police, the Gestapo and Abwehr (military intelligence agency) proved to be effective opponents to the resistance. In the early war period. The Germans were highly competent and brutal, the first French resitance groups amateurs. Few resistance members could withstand German torture. German agents easily infiltrated and tracked down resistance groups. Gradually resistance groups became more effective. They developed codes, complex communications networks, and security structures to protect members and information. The resistance relied on coded messages both to communicate with members and plan operations. Members were assigned code names. Operational units had their own cryptonym or symbols, meaning if they were discovered by the Germans, the codes of other cells were not discovered. Underground newspaper also published coded articles and drawings. The French were adept t using poetry as a means of sending coded messages. It was also used to identify each other as a members of a resistance group to each other. Radio Londres broacast messages inserted with the radio program in the form of personal greetings. They were often peculiar and obviously had hidden meanings intended to a specific audience. Individual underground cells knew what to listen for instructions. Their operations were primarily focused on preparations for D-Day. Reporting on German movements and preparations became more imprtant than attacks -- until D-Day.

Germany

A major problem in World War I was that once an offence was set in motion, the high command lost contact and the ability to direct forward elements. Advances in radio meant that World war II commanders could keep in contact contact with forward units no matter how rapidly they were moving. But this raised a serious problem in that radio broadcasts could be intercepted by the ememy. The German sollution to this problem was the Enigma Machine. This was an advanced electro-mechanical cipher machine. It was used by all branches of the German military including the Wehrmacht, Luftwaffee and Kriegsmarine. The different services developed different machines and varied in their operational procedures. The Enigma machines were the principal German device for secure wireless military communications throughout the War. The German military was concerned about security and thus developed increasingly complex types which made it more difficult for code breakers to crack. The most complex Enigma machine type was developed by the Krigsmarine for U-boat operations, in part because of rising U-boat losses. The Kreigsmarine also added a fourth rotor. The Germans also developed increasingly complex operating procedures. Enforcement of these procedures varied. The Luftwaffee was especially lax. Some commanders became concerned that the Allies might be breaking the Enigma codes. As a result, the Germans conducted investigations about this possibility. The German experts concluded, however, that Enigma was still secure. Their assessments proved to be inaccurate. A Polish mathematician played a key in cracking the German military's suposedly unbreakable cipher machine--Enigma. The Poles in cooperation with the French were able to construct an enigma machine which they turned over to the Britih just before the German invasion launching the War. Additional work done at Bletchly Park allowed the British by late 1940 to read large numbers of Luftwaffe messages. The Kriegsmarina code was also broken, but was more difficult because their operators were more careful to follow procedures and the fourth rotar. Many messages were read because operators did not follow procedures. The Royal Navy managed to obtain an intact Enigma machine and associated material needed to set the machines. Decoded Enigma traffic played a vital role in the Allied victory against the U-boats and in the cutting off of Rommel's supplies in North Africa.

Italy

We do not know a great deal about Italian code systems. Italy was the first of the hyper-militaristic Fascist states. Musolini amassed very substantial military services. The Italian economy was, however, not large enough to support such a lrge military. Itaklian soldiers were not well varmned and supported. Because of Mussolini's expansive ambitions and plans for military actions, secure codes were an obvious necesity. Italian code breakers, however, were not up to the challenge of 20th century codebreakers. General Vittorio Gamba, head of the Army's Servizio Informazioni Militari (SIM) turned up unannounced at Amtsgruppe Wehrmachtnachrichtenverbindungen, Abteilung Chiffrierwesen (OKW/Chi), OKW's cipher department (1938). Gamba requested cooperation in cryptology. [Christos T.] What he was interested in, however, was help in cracking foreign codes, not in strengthening Italin codes. The Italians even before the NAZIs seized power, purchased some early commercial versions of the German Enigma machine. As best we can tell, however, at the time Italy declared war on Britain and France (June 1940), the Italian Army was primarily using using World War I-style code books. The Italian Navy was more advanced thn the Army. They began using an Hagelin rotor-based cipher machine called the C-38 (early 1941). We think this is the machine that some authors refer to as the 'Italian Enigma'. It was much less secure thn the German Enigmas, espcilly the four rotor naval Enigma. We believe that the Italians used German Enigma machine when joint operations began (1941). The Itlians were apparently less cautious about security and procedural disipline than the Germans which helped the Bletchley Park code breakers. Curiously given the see-saw battles in the Western Desert, we do not note accounts of captured Enigma machines. The Italian codes were important not only because of Italian naval operations, but because supplies and reenfircements for the Afrika Korps was delivered by Italian convoys which became major target for the Rot=yal Navy, As the suplies were mostly deliverd to Tripoli in western Libya, the convoys were also attacked by RAF aircraft operatng from Malta.

Japan

Both the Americans and the British broke Japanese codes after World War I. The Japanese had no idea that their codes had been broken. The secret was never uncovered by the Japanese coubter-intelligence services. Rather the Americans announced what they had done. The unemployed American crytologist, H.O. Yardley, published a book describing his achievements. [Yardley] As a result, the Japanese changed their entire code and cipher system, closing off access to the Americans for several years. The Japanese developed a cipher machine similar to the German Enigma Machine which the Foreign Ministry used. The American code breakers referred to as Red. which the Foreign Ministry used. Subsequently they introduced a more advanced machine which the Americans called called Purple (1937). The Japanese Foreign Ministry considered it unbreakable and used it for their most sensitive communications. As World War II approached, American and British cryptologists began working together on Japanese codes. This was a very difficult task because so few Americans spoke Japanese. And the Japanese complicated task since they employed a jumble of kanji, hiragana, and romanized Japanese words. American cryptologists broke the Japanese diplomatic codes. They broke into Red before World War II. The cracked Purple after the War began in Europe, but before the Japanese launched the Pacific War. The resulting inteligence program became known as Magic. This did not prevent the devestating Pearl Harbor attack because the American naval crytologists had not yet broke into the naval code--JN-25. Subsequently American code breakers finally cracked the coveted Japanese JN-25. This played a key role element in the American naval victory at Midway (June 1942). The Imperial Navy was in the pricess of changing the codes, but their successful offensive in the South pacific had created many new posts and isolated facilities that the effort needed to destribute the updated codes took considerable time. Given the Yardlry relevations, one would have thought that the Japanese would have been very careful with their codes. Even after the American carriers unexpectedly turned uop in the Coral Sea and at Miday, Japanese naval authorities concluded that their codes were still secure. Breaking the Japanese codes also allowed American pilots to shoot down Adnmiral Yamamoto--the architect of the attack on Pearl Harbor. American cryptogists continued to gain valuable information during the New Guinea campaign (1943-44) and the critical Marianas campaign (1944). Ironically, Magic proved to be the best source of informatuon outside of Ultra on German operations. Japan and Germany were Axis allies. The Japanese Ambassador to Germany, Osima, was ardently pro-NAZI and wanted Japan to join in Barbarossa. He had very cordial relations with high NAZI officials. He thus obtained and relayed very accurate and detailed messages on to Tokyo about the conduct of the War in Europe. These messages as a reult of Magic were thus available to American officials. Through Magic intercepts, the United States learned of Operarion Barbarossa and were the source of the warning President Roosevelt gave Stalin (without devulging the source) just before the surprise NAZI attack.

Soviet

We do not have a good understanding of Soviet codes during World War II. There seem to have been quite a number of codes with several different vagencies having their own codes. In addition to the military services and Foreign Ministry, several other agencies had code systems. One was Soviet trade offices which had an especially important unit with a considerable amount of traffic working with the American on Lend-Lease. This group included the Soviet Trade Organization (AMTORG) and the Soviet Government Purchasing Commission. Other codes were adopted by Soviet intelligence (NKVD/KGB), Red Army military intelligence (GRU). Red Navy military intelligence (GRU-Naval). [Goebel] Presumabky the Red Air Force also had an intelligence unit, although we do not have details. We do not know if there was any central cryptology school or instituition providing technival information to thses various institutions or if the different agencies were on their own in developing codes. Not do we know if there were similarities withe codes adopted by these agencies. We have very little information as to the nature of the Soviet codes. Many of these codes were cracked during the War by the Finns, Germans and Japanese. A major step was the Finns seizing a partially burned Soviet code nook at the Soviet Embassy in Helsinki when the Germans launched Batbarossa (June 22, 1941). The Finns shared their find with the Germans and Japanese. We are not sure what inteligence coups resulted from this work. The Red Army launched several major offensives during the war in the East and German intelligence failed to provide alerts to any of these offensiveds. The United States also cracked some of these codes, by began working on them later (1943) and many were not read until after the War. Many of the messages the United States had to work with were messages associated with the Sioviet Trade Office involved with Lend Lease. The American decrypts are known as the Verona papers and provided insights into Soviet espionage operations in the United States. [Goebel] The only aspect of World War II crypthology that is not now available to historians are Soviet efforts at code breaking. The Soviets and now the Russians have been reluctant to open their archives to historians.

Sources

Goebel, Greg. "Verona" 7.5. This is a chapter in a larger work, but it is unclear how to site the overall work.

T., Christos. "Italian codebreakers of WWII," Christos military and intelligence corner (August 29, 2012).

Yardley, Herbert Osborne. The American Black Chamber (1931).







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Created: 5:30 AM 2/23/2011
Last updated:8:59 AM 3/2/2022