*
war and social upheaval: World War II -- German code systems
World War II: German Code Systems and Ultra
Figure 1.-- Britain and Germany were still class-bound socities at the time of World War II. This meant that few working-class boys continued their educations beyond primary school. Ironically it would be two working-class scholarship boys, Bill Tutte and Tommy Flowers, who would perform the phenomal intelectual task of cracking the top German code of the War -- Lorenz/Tunny. Lprenz was the system used by OKW and thus far more compicated than Enigma. And the two ciode vbreakers at Bletchely Park managed this just by listening to the wierd sounding sounds recorded by the Y-Service. They never had a machine to examine or any code books. It was acts of formidable raw genius. This is Bill Tutte at his Cheveley Village School about 1926. He is the boy at the lower right. oNe of the great questions of World War II was why were the Beits and Anmericans so good at code craking abd the Germans and Japanese so poort. And why do we know nothing about the Soviets.
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 British 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.
World War I
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. Commanders were constantly frustrated by the fact that no matter how carefully planned by the fact that once they set an offensive in motion that they lraely lost control. No battle plan in the end survived contact with the ememy.
Deutsche Reichsbahn
The German engineer Arthur invented an electonic encryption decice at the end of World War I (1918). It was a way of automating the time consuming proce of encrupting and decrypting sensitive infornation. Scherbius helped found a compamy to market his new machine--Scherbius & Ritter. They began marketing it as a cipher machine (1923). The commercial brand name was Enigma. [Singh] The initial intended market was commercial. Their most important customer was the German Railway System. The Deutsche Reichsbahn Gesellschaft (DRG usually DR for short) was the state-owned German National Railway. It was created after World War I from the regional railways of the individual states that had been united (1870). The DR is believed to have been the largest commercial enterprise in the capitalist world in the inter-War era. The German railwat systen had come about to service military needs in Prussia and also largely industrial needs in much of the rest of Germany. It was extensive, complex, and highly efficent. The old saw that the trains ran on time is an understatement. The DR for security reasons needed a way of transmitting secured communications. And Enigma was the answer. But importantly after it was adopted by the Reichwehr before Hitler seized power, it was not a secret device. It was sold to other firms, including foreign comoanies. And because the DR was such a massive operation and conncted to the rail system of neigboring countries, the existence of the device was known outside of Germany, including as the device took on military significance, most notably Poland. THe fact that the Reichwehr did not build a secret device, but instead purchased a commercial product would have emense consequence for the conduct of World War II.
Blitzkrieg Theory
German military theorists were working out the basics of Blitzkrieg (the term came from Goebbels) after the War began)in the 1920s before Germany had a large military force or the armaments to carry it out. Lack of control of moving units had proved a major problem in World War I. 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 was the Enigma Machine. An integral part of Blitzkrieg was command and control of rapidly moving mobile formations and this was only possible through radio communications.
Enigma Machines
The German sollution to the insecurity of radio messages was the Enigma Machine. This was an advanced electro-mechanical cipher machine originally developed by the German Railway Service. 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 during the 1930s and throughout the War.
Y Service
The Y Service was an already established British opeation. The operation had begun during World War I focusing on intercepting German radio (wireless) signals. To crack Enigma and other German messages, the British first needed mesages to work with. These wre provided by the 'Y' Service. This was a chain of wireless intercept stations located throughout Britain. There were also sites in countries/colonies overseas. Royal Navy ships at sea also intercepted messages. The Y Service consisted of thousands of wireless operators, consisting of many civilians, including Wrens, WAAF personnel and members of the ATS. They tracked German and other enemy transmissions all over the frequency dial. They carefully logged every letter or figure. British ham radio short wave enthusiasts reported that they were picking up voice conversations from Luftwaffee planes. These messages were then forwarded to Station X--Bletchely Park. Here they were not only decoded, but fitted together like a gigantic jigsaw puzzle to create a composite view of enemy operations and intentions. The Y Service was also did important directionl finding, especially important during the vital Battle of the Atlantic.
Initial Codebreaking
The Allied effort to crack the Enigma machine began even before Hitler''s rise to power. Hans Schmidt was a clerk in the German government codes department. His brother who was a high military commander got him the job. Schmidt wanted money and used his position to get it. He contacted French intelligence (1931) and offered to sell them secret documents. Among the documents was the Enigma machine's operating manual and settings lists. The French shared the windfall with British code breakers. Tghey made little profress in crascking the transmissions.
They decided tp share the material with Polish code breakers. It was the Poles who concluded that the only way to decipher Enigma messages was to actually construct an Enigma-like machine. They very quickly did just that (1932). Thus for much of the 1930s, the Poles were able to read many German military transmissions. Brilliant Polish codebreakers with limited resources managed to dechipher some German Enigma messages. They were at first reluctant to fully share their work with the British and French. This changed after Munich when Hitler began to move against the Poles. The Poles built new mechanical cryptanalytic aids which they called bombes as well as Enigma replicas and presented them to their new Allies (July 1939). After the German invasion, the Poles managed to close down their code breaking operation anf the German occupation forces never learned of what they had accomplished. The work by the Poles, however, played an important part in the future success success of Ultra--the British code breaking effortb at Blechly Park.
The German military in the 1920s developed the theory of Blitzkrieg . Hitler financed the countruction of an advanced military to conduct Blitzkrieg. Hitler and the NAZIs planned from the beginning for a massive rearmament program--Aufr�stung. NAZI propaganda promoted the idea that Germany must rearm. The NAZI objectives could in fact only be achieved by war. The NAZIs did not, however, begin a massive rearmament program immediately upon seizing power in 1933. Hitler's first objective was to secure control of Germany and he did not want to precipitate foreign intervention before he was ready. The German military itself has already sponsored secret armament programs during the Weimar era in violation of the Versailles Treaty. The NAZIs thus had a solid foundation upon which to base a revived military. The NAZIs sharply expand weapon research. The German military expanded in secret during 1933-34. Hitler by March 1935, felt sufficiently secure to publicize his military. The NAZIs announced that they expansion - which broke the terms of the Versailles Treaty. Europe learned that the Nazis had a modern 2,500 plane Luftwaffe and a Wehrmacht with 300,000 men. Hitler publicly announced that he was instituting a compulsory military conscription and planned to expand the Wehrmacht to 550,000 men. Actual armaments production began in earnest in 1936. The NAZIs in 1936 doubled armaments spending over 1935 levels. It was in 1936 that NAZI arms spending first exceeded the combined total for transportation and construction spending. The nature of arms spending also increased. NAZI arms spending initially focused on research, development, and capital investment. The NAZIs in 1936 began concentrating on producing actual military equipment. This is one of the least economically beneficial types of government spending.
Security
The Germans as war approached made cryptographic improvements that rendered much of the Polish work moot. The Polish work was an important beginning and the British and French had greater resources to attack the Enigmna problem. 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.
The code name for the British effort to crack the German military Enigma cipher machines was called Ultra. It was one of the most closely guarded secrets of the War. It was conducted at a country estate called Blechley Park. With the help of the Poles the British began working on the Enigma code machines that the German military used for radio communications. Effctive German communications were part of the reason for the victories in Poland and France. The French General Staff for example was using messengers to communications. While effective, the use of messages sent by radio meant that German military communications were vulnerable. The German relying on their preceived notions of supperiority were convinced that their Enigma cipher machine could not be ceacked. The Germans did not know of the Allied success until well after the War. British code breakers at Bletchley Park faced different problems with the Wehrmacht, Luftwaffe, and Kriegsmarina code. The Luftwaffe code proved the easiest to crack, primarily because flushed with sucess, the Luftwaffe was careless about following established security procedures. Many messages were read because operators did not follow procedures. Alan Turing played a key role. The British suceeded in dechipering some Luftwaffe messages (May 1940), although regular and timely decoding was not possible until the end of the year. (We have noted different assessments as to how useful Ultra was during the Battle of Britain.) Working with uncoded German radio messages also provided valuable information. This provided valuable intercepts with infornmation on force strength and targetting was available to the RAF. Dechipering Naval messages proved more challenging. The Kriegsmarina Enigma msachines were also cracked, but was more difficult because their operators were more careful to follow procedures and a fourth rotar was eventually added. The Royal Navy managed to obtain an intact Enigma machine and associated material needed to set the machines. Cracking the Kriegsmarina Enigma machines and Shark code played a major role in the defeat of the U-boat campaign in the North Atlantic.
Siemens & Halske T52 Geheimschreiber
The Germans invaded and occupied Norway (April 1940). A substantial force of some 0.5 million men was eventually maintained there. Hitler was convinced the Allies were planning to invade. The Germans began using a teleprinter circuit which fot geographic reasons had to run through Sweden. The Swedes from the beginning secretly tapped the line (May 1940). The mathematician and cryptographer Arne Beurling very easily in only 2 weeks cracked the two earliest models. All he needed was pen and paper. The device the Germas were used was the T52 manufactuted by the German Siemens & Halske electrical engineering compamy. T52 was known as the Geheimschreiber (secret teleprinter) or Schlüsselfernschreibmaschine (SFM).It was different than Enigma because it was transmitted over cable wires and not broadcast over the airways making it difficult to intercept-a significant security factor. The Swedish telephone company, Ericsson, manufactured compatable machines. They could decode messages once the key settings had been computed by hand. The Swedes were thus able to read traffic in the system for 3 years. And this was not just messages the Germans sent fromm Oslo. They could read Germans messagessent from Finand and the messages the Germans sent from their Stockholm Embassy. The messages to and from Finland were particularly imprtant. They would have involved messages dealing with the German Barbarissa Plan to invade the Soviet Union. The Swedes manage to intercept some 0.5 million German messages and sucessfully decrypted 350,000 of them before the Germans learned of the Swesish operation. The Germans introduced a new T52 machine (1942), but the Swedes quickly solved it. The Germans developed further refimements (mid-1943). The Swedes were unable to break the new machine. . [Gannon, pp. 157-58.] We are not sure how extensivelt the T52 was used. e know it was used in the Nordic coutries and southern Europe. We are unsure to what extent it was used in the East (occupied Soviet Union). The Allies did not encounter the T52 messages until they got back on the Continent or at least close to it where there were cable connections -- Sicily (1943). Bletchley had some success in cracking it, but only partial success in large measure because they encounterd the improved T52 system.
The Americans
American code breakers focused on the Japanese before entering the War. The British were also working on the Japanese codes. The Americans made considerable progress, cracking the diplomatic Purple code, but not the naval code until after Pearl Harbor (December 1941). American and Britain began cooperating on code breajing a year before Ameruica entered the War (November 1940). Once in the war, the United states began working on the German codes as well in close cooperation their British allies.
Enigma was not the only German cipher system with which the Allies had to conted. The German High Command (OKW) asked the Lorenz company to build a high security teleprinter cipher machine to give them the ability to send and receive radio messages in absolute secrecy. This was a system even more secure than the Enigma machines. The Lorenz company came up with a cipher machine based on modular arithmatic. [MacCallum] It employed the additive method for enciphering teleprinter messages. The system has been invented by an American, Gilbert Vernam (1918). Teleprinters are not based on the standard 26-letter English alphabet (which is very similar to the German alphabet) and Morse code on which the Enigma machines are based. Rather teleprinters use the 32-symbol Baudot code. This consists of five channels each of which is a stream of bits which can be represented variously as no-hole or hole, 0 or 1, dot or cross. Thus, the many rotors and other complicatins the Grrmans devised meant that the Lorenz code presented an a complexity an order of magnitude deyond that of Enigmam. It was the most sophisticated and complex of the Axis code systems. And caried the most secret German messages. Enigma was more of housekeeping messages for the German miliarry. Bletchly had to piece the many diaparate messages togethrr to get insights into German operations. Lorenz carried actually messages dealing with German strategy, messages between OKW (which invilved Hitler himself) and the major far-flung German command posts. The British called it Tunny. There was a fairly small number of stations for sending and receiving Lorenz messages. Berlin and Könningsberg were at the heart of it. Each link in the system had a fish name, the overall name was called Tunny. Incredably Bletchely code breakers were able to crack Lorenz with raw brain power. Cracking Enigma was aided by the Poles who built machines as well as actual German Enigmas and code books which the British captured. The Lorenz team had nothing to work with other than Y-Service intercepts. And as the intercepts were not in Morse code. Lorenz was a huge challenge from the beginning. Incredably two working class scholarship boys not only cracked it, but developed an automated process for decyphering the decrypts, essential in real time. John Tiltman sussed out that it was a Vernam cipher and cracked early versions. Bill Tutte, who Turing turned down for his Enigma team, played a key role in solving the the more advanced versions. As with Enigma, German operational shortcomings, opeartors not following procedures, played a key role in the British success. The problem for the British was that it was a laborious process, especially as the Germans kept adding complications. Here Tommy Flowers, another schlarship boy, delivered the coup de grace. He automated the process. His idea was at first dismissed and he had to use his own money. His process was eventually recognized and he created the first electronic computer--Colossus (December 1943). This mnean that the Allies as preparations for D-Day began had a direct look into Hitler's mind that Enigma did not provide. All of this was done without ever seeing a Lorenz machine until the last months of the War. It was all a matter of virtulaly unbelievable raw genius. The Soviets presumably acquired Lorenz machines much earlier than the Allies. We have no idea what they did with the Lorenz machines they much have acquired during their various offensive operations. Soviet/Russian historians have not addressed this matter.
The Soviets
As far as we know, the Soviets never cracked the German Enigma and Lorenz machines. After the offensive before Moscow (December 1941), they must have come into possession of some, probably many of the machines and code books. They probably also had capturfed operators, and they had ways of making them talk. We do not know, however, to what extent they tried to crack the codes. The Soviets and now the Russians have never released information on this subject. It is inconcievable that the Soviets did not work on Enigma and code breaking. And given the vRussian menchant for matahematics they had some of the same skills the British code breakers had. We simply do not know anything about their work. And as far as we know, it is a subject that the Soviet/Russian historians have not benn allowed to address.
Allied Usage of Ultra Decrypts
Ultra Decrypts behan to flow out Of Bletchely Park beginniung woth the Norway opertation. Decryots alobe do not win battles. The British needed military forces to actually win battle. Here it was the Royal nNavy that was best positionged. Unfirtunately it was Admiral Dönitz that was most concerned about security. He insisted on an extra rotor and saw to int that naval Enigma operators most closely followed proscribed procedures. Fortunately Döntiz's insistence on closely meant that Bletchely had a geeat number of messages to work with. Dönitz closely controlled from his French headquarters. This meant a massive amount of signaling goung back and forth, especially when the wolfpack operatiins began. As the number of U-boats increased, they posed a real threat to the British war effort. Decoded Enigma traffic played a vital role in the Allied victory against the U-boats in the vital Battle of the Atlantic (1941-43).
Heer and Luftwaffe messages were decrypted earlier. Unfortumately the British did not at first have the military capability nof taking advantage of what they picked up. The British learned of German intentions in the Balkan states, including the invasion of Yugosavia and and Greece. Such intelligence, however, was of limited value when the British Army did not have the military capability of taking on the Germans. The Soviets did have a substantial military force and based on Ultra, the British warned Stalin about Barbarossa (June 1941). The Americans based on Mah=gic also warned Slain refused to believe them and the Soviet people paid the consequences in blood.
For the first 3 years of Bomber Command’s air war on the Reich yielded little useful intelligence.
British forces first began reaping the nenefits of Ultra in he Mediterranean. Ultra first provided actionable information on the air and ground war as well as Itlaian naval moperations. This included insights into what the Germans and Italians were doing in the Mediterranean and supplied Allied naval and air commanders with detailed, specific information on the movement of the Italian fleet. They also produced dettails on Italianamd convoys carrying supplies to the Africa Korps. And then in the closing phase of the Tunisuan oerations (March 1943). Anglo-American air forces operating in the Mediterranean aided by Uktra shut down Axis seaborne convoys comoletely. Ultra decrypts reported thatbthe Germans placed the blame on Allies spies. they looked everywhere except their own encrypted transmissions--primarily because they were confident with their apparent technological genius.
This British Arny first began to achieve some successes in the Western Desert as the Italainas and than the Germans attempted ri seize the Suez Canal.
Ultra gave the British an accurate picture of The Afrika Korps tank strength during the fifgting in the Western Desert (1941-42). It also helped cut off Rommel's supplies in North Africa by lovating the Itakian convoys. .
In the battle for Sicily, it alerted the Allies to German fuel and ammunition shortages and to locate Axis dispositions on the airfields of Sicily and southern Italy.
And as preparations for D-Day began, Lorenz provide invalauable insights into German preparatioins, in particular the extent that the Germans were falling for the D-Day deceptions.
German Military Doctrine
One often ignored aspect of the radio technology and the German Enigma Macine was the impact on German military doctrine. The Prussian military was renowned throughout Europe. (Americans in the Revolutionwary War got a taste of this when they faced off with the Hessians who were not nearly as renowned as the Prussians.) Prussia itself was apoor state, often described as an army attached to a country. The relative poverty of Prussia was one reason such great attention was given to a professional standing army. A key aspect of Prussiam military dictrine was that commanders in the field should be given great latitude and authority. This was almost required by an aggressive force like the Prussian Army because of the slowness and unrelability of communications. One renowned Prussian commander who ignored Frederick the Great's ordered famously replied toi him that after the battle his head would be at the King's diposal. Prussian military dictrine was ingherited by the German Empire and was still largely intact at the onset of World war II. Radio communications chamged this. Suddenly OKW and Hitler had the capability to communicate instantaneously with field commanders. The Wehrmacht was allowed to operate without much interference in the first two years of the war, but this changed with Barbarossa, especially when progress began to slow. Historians argue as to what extent this affected the outcome of the War, but Hitler had the ability and frquently used it to interfere in the operatins of field commanders.
