Italian codebreakers of WWII

Fascist Italy was one of the main Axis powers. At the start of WWII Mussolini remained neutral but he joined the war in 1940 after it was obvious that France would be defeated. From then on Italian troops fought in the Balkans, against the Soviet Union and in North Africa.

Mussolini’s adventurism led to military reverses as the Italian economy was not mobilized for war and the military did not have modern equipment and training. This forced the Germans to come to their aid in the Balkans and in North Africa. However that does not mean that the Italian military didn’t fight bravely. In the Mediterranean it was the Italian navy that successfully transported troops and supplies to the Axis forces led by Rommel. Italian troops fought bravely in North Africa even though they were deficient in modern weapons and lacked mobility. The Italians may have lacked modern weapons however they did have a small but effective cryptologic capability.

The Italian Army and Navy had separate codebreaking agencies that managed to exploit important foreign crypto-systems. The Army's codebreakers could read the codes of several foreign countries, including the communications of US military attaches and especially those of a mr Fellers in Cairo. The Navy's codebreakers were very successful with Royal Navy codes and cyphers. The Italian codebreakers were assisted in their efforts by the good work of a special undercover squad that entered foreign embassies and copied the codes.

Army agency

The Italian army’s intelligence agency SIM (Servizio Informazioni Militari) had a cryptanalytic department that attacked foreign crypto-systems. This section was headed by General Vittorio Gamba and was located in Rome. Personnel strength was roughly 50 people (half cryptanalysts-half linguists and clerks).

The cryptanalytic department was divided into three sub-sections:

1). Diplomatic

2). Military and Research

3). Commercial

Personnel were moved from section to section based on the current priorities. The diplomatic section was subdivided into nine groups. The military and research section had 5 cryptanalysts. The research section was responsible for the initial ‘break’ into hard systems. Results were sent to field units. The commercial section’s task was to check Italian commercial codes for irregularities.

On average 8.000 messages were intercepted each month, 6.000 were studied and out of these 3.500 translated. The codes of several countries were read including France, Turkey, Rumania, USA, Britain, Yugoslavia and the Vatican. According to post-war reports there was a serious shortage of foreign speaking personnel and a lack of funds. There was also lack of IBM equipment for statistical work. The Italians used a small number of IBM punch card machines for cryptanalysis. Initially IBM machines were used only at the offices of the Watson Corporation in Rome. However it was only in the last stages of the war that these machines were used regularly.

Intercept section

The intercept section of SIM was the one that provided messages for cryptanalysis. It had 4 stationary intercept stations in Italy and 7 mobile units in Italy, the colonies and the occupied territories.

There was poor liaison between the intercept section and the cryptanalytic department and all requests had to go through SIM headquarters.

The Sezione P unit

The Italians were often able to read foreign codes without the use of cryptanalysis. Their secret? They had a very efficient undercover team that entered foreign embassies and copied codes and ciphers.

This was the Extraction Section (Sezione Prelevamento), headed by colonel Manfredi Talamo of the Carabinieri (military police). Its operatives were experts in entering guarded areas and opening locks. It was this unit that copied the Military Intelligence code No11 used by the US attaché in Cairo colonel Bonner Fellers.

Cooperation with foreign countries

Cooperation with Germany

General Gamba arrived unannounced at OKW/Chi in 1938 and requested cooperation in the cryptanalytic field. The Germans initially agreed to share results on French diplomatic and military systems. This collaboration was expanded and provided the Germans with important cryptologic material like the US Military Intelligence code, however relations between OKW/Chi and SIM were not as close as with the Finns and the Hungarians. According to Fenner, head of the cryptanalysis department of OKW/Chi, the Italians took too long to respond to requests or did not send the agreed upon material. An even greater problem was their resistance regarding the change of their weak cipher systems. As the war went on relations became strained since the Germans came to distrust the Italians.

Cooperation with the German army‘s signal intelligence agency - OKH/In 7/VI seems to have been poor as the Germans had little respect for Italian cipher security.

Cooperation with Hungary

According to ‘European Axis Signal Intelligence in World War II’ vol8, there was cooperation between the Hungarian cryptologic service and the Italians.

In page 21 it says:

Liaison with the Italians on cryptanalytic matters appears to have been very good. The Hungarians maintained liaison officers in Rome and made the results of their work available to the Italians.

Cooperation with Finland

Some intercepted traffic was sent to the Finnish cryptologic service.

Notable successes

Fellers code

In late 1941 the Sezione P unit managed to infiltrate the US embassy in Rome and copied crypto material. One of the systems copied was the Military Intelligence Code No11 used by military attaches. This allowed the Italians to decode the messages of US attaches from embassies around the world.

The most important transmissions were those of colonel Fellers US ,attaché in Cairo. Fellers was a graduate of West Point and former assistant of General Douglas MacArthur. He was posted to Cairo in October 1940. His job was to provide Washington with detailed information on all important military operations. The British gave him access to their facilities and shared sensitive information on upcoming operations. All this information was extremely important for the Axis side. The Italians shared the Military Intelligence code with the Germans.

According to Fenner, head of the cryptanalysis department of OKW/Chi, the Italians sent him a copy of the codebook in 1941 but not the encipherment tables. He got these from the Hungarians. Both sides were able to read the Fellers messages during the first half of 1942.

Yugoslav Army code

In 1940 the Italian forces in Albania invaded Greece. The Greek army was able to drive them back and hard fighting ensued.

Practically all the Italian forces were concentrated in the south of Albania. This meant that the Albanian-Yugoslav border was not well protected. A sneak attack by Yugoslav troops had the potential to destroy the Italian forces.

In April 1941 this operation was put in motion by the Yugoslav high command. The Italians were in a tight spot however they were able to cope with the situation through their mastery of Yugoslav codes.

The Italian codebreakers sent two messages to the Yugoslav divisions, written in the correct format and ‘signed’ by General Dusan Simovic, head of the new government. These said:

1). To the Cetinje divisional headquarters:

Subordinate troops will suspend all offensive action and retire in the direction of Podgorica, organizing for defense.

2). To the Kosowska Mitrovica divisional headquarters:

Withdraw immediately with all subordinate troops back towards Kosowska Mitrovica.

Since the messages were enciphered with the Yugoslav army code and had all the signs of a real order they were accepted by the divisions and the offensive was halted! The Cetinje division requested confirmation from HQ but none came and it too retreated. When the next day HQ responded that no retreat had been authorized it was too late. Italian military units had occupied the abandoned areas and the Yugoslavs had bigger problems to handle as the German invasion had led to the collapse of their military forces.

Naval agency

The naval intelligence agency SIS (Servizio informazioni Speciali della Royal Marina) was divided into 4 branches. Branch B (Beta) was tasked with signals intelligence. It was subdivided into cryptanalysis, interception and direction finding, security and clandestine radio intercepts.

The cryptanalytic department was located in Rome and headed by Commander Mario De Monte. In the 1930’s they solved several French naval systems. During the war the emphasis was on British naval and naval aviation codes. Low level British naval codes were easily solved. The Italians also read the Royal Navy’s Administrative Code (used from 1934 till August 1940), the Naval Code No1 and No2 (used from August ‘40 till March ’43) plus the Naval Cypher No1 and No2 (used from 1934 till January ‘42). They acquired Naval Cypher No3 (Anglo-American Cypher used from June ’41 till June ‘43) from the Germans and were able to solve the encipherment. For speeding up their work they used punch card equipment in 1942.

The Italian Air Force Intelligence Service (Servizio Informazioni Aeronautica) relied on the Navy department for interception and cryptanalysis. In 1941 the Airforce set up its own intercept station and sent the messages to the Navy.

Intercept section

The interception and direction finding department of Branch Beta supplied messages and had 7 main stations in Italy and its possessions. The intercept network was comprised of the following stations:

- Monte Rorondo, near Rome with subcentre at Licola.

- Tirrenia, with substations at Arma di Taggia and Toulon.

- Porto Palo, Augusta with substation at Favignana.

- Pula, Sardinia with substation at Porto Torres.

- Rhodes, Greece.

- Tripoli, Libya.

- Benghazi, Libya

Additional material was received from the Germans. The daily average was 3,000 messages. Special intercept units were also based onboard flagships (squadrons, divisions and convoy escorts) so that the intercepted messages could be exploited as quickly as possible and the information communicated to the naval commanders.

Cooperation with the Germans

During the 1930’s liaison was established with the German Navy’s cryptanalytic service B-Dienst and some information on French codes was exchanged. The Germans also gave information on the British Administrative code but did not share their work on other systems.

After Italy’s entry into the war relations became much closer and information was exchanged on the Naval Cypher and Naval Code. Finally in 1942 the Naval Cypher No3 (Convoy Cypher) was shared.

There was a daily exchange of recovered code groups via teleprinter and every week a written report was sent. Branch Beta also received messages from German intercept units.

Battle of the convoys

In the period 1940-1943 the naval codebreakers concentrated on the codes and ciphers of the Royal Navy. The call signs, messages and volume of traffic of British units were analyzed in order to build up the British order of battle and identify the movement of units in the Mediterranean. Branch Beta summarized this information in a daily bulletin submitted to all naval commands.

The value of codebreaking and signals intelligence was recognized by the Navy’s high command and there was close cooperation between Branch Beta and the operational command of the Italian Navy. According to Admiral Franco Maugeri, head of the SIS:

‘The departure of an enemy naval force or a convoy from East or West never escaped the SIS, and it was almost always possible to establish within a few hours its composition and even its objectives; which permitted immediate counter measures on the part of our naval command, and the most Important naval encounters (Battle of Punta Stile, of Cape Tulada, of Cape Matapan, the two actions off Sirte, and that of Pantellaria) originated through information from the SIS’.

Another advantage from reading British naval codes was gained by learning of their plans to attack Italian convoys to N.Africa. Messages from British naval aircraft (Fleet Air Arm) could be decoded very quickly and these gave an insight into British operations, especially against Italian convoys. In those cases the Italian command quickly warned the convoys by sending them top priority messages called PAPA (Precedenza Assoluta sulla Precedenza Assoluta) so they could alter their course.

Work after the surrender of 1943

In September 1943 the Italian government surrendered to the Allies and tried to exit the war. Unfortunately the Germans were expecting such a move and quickly occupied the country.

Mussolini was established as head of the Italian Social Republic covering the German occupied areas. This state continued to use a small number of SIM codebreakers. They mostly exploited systems already broken before the surrender. The main emphasis was on diplomatic messages in order to get information about conditions in the liberated areas.

The Germans were not helpful and they did not exchange results with the codebreakers of the Social Republic.

Conclusion

Italy entered WWII hoping to exploit Germany’s victory for its own gains. When the war dragged on the Italian economy and the military forces were unable to deal with the new situation and the country tried to surrender to the Allies in 1943. Despite these shortcomings Italian army units and the Navy fought well in the Mediterranean and North Africa.

In the cryptologic field the Italians were hampered by the lack of personnel and resources. Still they were able to exploit several important enemy systems and provided the Italian leadership with the confidential messages of several foreign countries. In the case of the Fellers messages and the Yugoslav Army code their efforts truly had a strategic effect. Their naval codebreakers successfully solved the codes of their main opponent, the Royal Navy, and took advantage of this in several naval engagements.

Considering the resources at their disposal it would be hard to ask more of the Italian codebreakers.

Sources:

HW 40/75 ‘Enemy exploitation of Foreign Office codes and cyphers: miscellaneous reports and correspondence’, TICOM DF-187D ‘Relations of OKW/Chi with foreign cryptologic bureaus’, ‘The codebreakers’, ‘European Axis Signal Intelligence in World War II vol8’, Cryptologia article: ‘The cryptographic services of the Royal British and Italian Navies’, International Journal of Intelligence and Counter-Intelligence article: ‘Left in the Dust: Italian Signals Intelligence, 1915-1943’, TICOM I-12 ‘Translation of the Preliminary Interrogation of O.R.R. Tranow of 4/SKL III/OKM, carried out at Flensburg on 24-25 May 1945 by TICOM Team 6’, Wikipedia, Naval War College Review article: ‘The Other Ultra: Signal Intelligence and the Battle to Supply Rommel's Attack toward Suez’,
‘Italian Communications Intelligence Organization’-Report by Admiral Maugeri with U.S. Navy Introduction, TICOM D-71 'German and Italian Correspondence on Miscellaneous Cyphers', CSDIC/CMF/Y 29 ‘First detailed interrogation of Samarughi, Giuseppe’, CSDIC/CMF/Y 4 ‘First detailed interrogation of Bigi, Augusto’, CSDIC (main)/ Y 12 ‘First detailed interrogation of Vassalio Todaro’

Book review - Brute Force

Practically all histories of WWII follow the same structure: initially the Axis powers manage to surprise the Allies and win some great victories but then the forces of democracy (plus the Soviet Union) rally up the troops and start winning the battles thanks to Allied superiority in strategy, intelligence and so on. The outcome of the war is always close in the balance. If the Germans or the Japanese had made some different decisions things would be very different and the Allies would be in danger of losing the war.

A book that takes a completely different view is ‘Brute Force’ by John Ellis. I think this book is one of the most important ones written about WWII.

 

The main point is that based on the Allied economic and manpower potential even a negotiated surrender was beyond the grasp of the Axis forces.

Ellis shows the incredible disparity between Axis and Allied war production (weapon systems and raw materials) in the statistical appendix at the end of the book. Some examples for 1939-45 production:

1). Coal (million metric tons): Axis-2.624 , Allies-4.283

2). Crude steel (million metric tons): Axis-191 , Allies-497

3). Aluminum ( 000 metric tons): Axis-2.503 , Allies-4.642

4). Crude oil (million metric tons): Axis-50 , Allies-1.043

5).Tanks and self-propelled guns: Axis-51.845 , Allies-227.235

6). Combat aircraft: Axis-145.584 , Allies-417.219

7). Military trucks and lorries: Axis-594.859 , Allies-3.060.354

This huge material superiority should have made WWII easy to win for the Allies.

The problem for the Allies is that they made very poor use of their numerical superiority. Both in theatres against Germany and in the Far East against Japan they misused their resources.  

In the Battle of France the Germans did not have numerical superiority. In fact their armored force was inferior both in quantity and quality compared to the Franco-British force.  They won by concentrating their mobile forces.

The Battle of Britain is supposed to be an example of the outnumbered RAF winning against the superior Luftwaffe. However if we look at fighter strength  things were much closer.

In North Africa the Brits managed to lose countless battles due to their lack of coordination between infantry, armor, artillery and airpower. The author points out that in the Second Battle of El Alamein Montgomery had significant numerical superiority and excellent intelligence on the enemy forces but still could not cut off and destroy the Africa Corps.

In Italy the Germans proved masters of defense and held on to half the country with limited forces. Allied operations showed lack of initiative and made very slow progress.

In Western Europe the Allies suffered heavy losses in Normandy despite having numerical superiority and air dominance. When they broke out in late July they were unable to cut off and destroy the majority of the German forces in the Falaise pocket. The same thing happened in the Battle of the Bulge. The German forces were defeated but not surrounded and destroyed.

In the Atlantic the Germans started with a very small submarine force and it took them too long to build it up. In the meantime the Allies were able to produce more ships than the U-boats could sink and build up their defenses (surface ships, escort carriers, long range naval aircraft). However it took too long for the Allies to build up their long range naval recon squadrons.

In the air war the performance of the RAF’s Bomber Command is criticized for being ineffective in the period 1939-42 despite receiving a large part of the defense budget. In the second half of the war the fixation with the night bombing of cities did not contribute to the dislocation of German industry nor did it knock Germany out of the war as was claimed by the RAF leadership. Moreover these missions had a very high loss rate for Bomber Command crews.

In the Eastern front the Germans were able to inflict very heavy losses on the Soviet military, yet the Soviets not only made up the losses but greatly expanded the size of their army. No matter how many formations the Germans surrounded and destroyed the Russians were able to field new ones. On the other hand Soviet victories were won at great cost in blood.

In the Far East the US Army and the US Navy fought two different wars. The Army fought in the South West Pacific while the Navy sent its Marines to retake islands of no strategic value in the Central Pacific. McArthur’s advance in New Guinea and the Philippines cut off Japan from its major raw material centers (especially oil) in South Asia. On the other hand the Pacific islands could have been bypassed. This duplication of effort was a complete waste of resources.

The author makes a convincing case that in all these campaigns  the Allies misused their numerical (and often qualitative) superiority thus extending the war.

German disinformation operations - The 1930’s crises and the mighty Luftwaffe

In the 1930’s Hitler was able to outmaneuver the Franco-British alliance and achieve his foreign policy goals without a shot being fired. After gaining power he reintroduced military service and rebuilt the armed forces. In 1936 he remilitarized the Rhineland. In 1938 he annexed Austria and parts of Czechoslovakia and occupied the rest in 1939.

At that time Germany was in the process of rebuilding its armed forces. A new German army could not be built overnight and in the meantime France had the largest and best trained and equipped army in Europe. At sea the huge British fleet could easily blockade Germany.

How could Hitler outmaneuver his opponents when they had the upper hand militarily?

The only way for Hitler to pursue his policies was to use the Luftwaffe as a propaganda weapon in order to intimidate his opponents.

In this effort he was greatly assisted by the popular belief in the superiority of airpower and the ability of the bomber to annihilate population centers.

The unstoppable bombers and the knock-out blow

In the inter-war period world opinion was fascinated by the progress of aviation. Military officers disgusted by the senseless slaughter of the First World War formulated new theories of war.

Instead of having millions slaughter each other in the trenches countries could invest in powerful bomber forces that would quickly destroy the enemy’s population centers and industrial facilities.

The ‘prophets’ of this new strategic bombing theory were Billy Mitchell in the USA, Giulio Douhet in Italy and Hugh Trenchard in the UK.

Popular authors wrote best-sellers, such as ‘The gas war of 1940’, about coming wars that would lead to the annihilation of cities by bomber forces.

Western leaders were terrified of the knock-out blow, a sneak attack on their capitals by a huge enemy bomber force. Official estimates were for hundreds of thousands of casualties and the collapse of civil order.

Military theorist Major-General J.F.C. Fuller said:

London for several days will be one vast raving Bedlam, the hospitals will be stormed, traffic will cease, the homeless will shriek for help, the city will be a pandemonium. What of the government at Westminster? It will be swept away by an avalanche of terror.

The Germans worked hard to exploit these phobias.

German successes in airshows

During the 1930’s German planes took part in many international airshows and impressed observers with their performance.

 

 

For example the Bf-109 equipped with a special 1,650 HP engine won in many categories in the 1937 Zurich air show. The prototype Bf-109V1 set a world record by reaching 755km/hour by using a 2,300 HP engine but the Germans called it Bf-109R to give the impression that it was a model in production.

The Dornier Do-17 bomber also took part in the Zurich competition and outflew all the foreign fighters. Again it was not the operational model but a prototype with a special set of 1,000 HP engines.

Outside observers had no way of knowing that the performance of these planes was not comparable to the standard models.

Colonel Lindbergh’s trips to Germany

Colonel Charles Lindbergh was a celebrity in the 1930’s and when he visited Germany, between 1936 and 1938, he was given a tour of Luftwaffe airports and production facilities.

In his reports to US military authorities he stressed that the Germans were world leaders in a series of aviation technologies.

His statements to the press presented a powerful Luftwaffe equipped with thousands of modern planes.

Airpower and the Spanish civil war 1936-39

The Germans sent a small air detachment equipped with fighters, bombers and recon planes to fight for the Nationalists in Spain. This unit gained world fame far in excess of its contribution to the military campaign.

Pro-communist propaganda did the Germans work for them by portraying German bomber attacks as holocausts.

The well known Guernica story is a case in point. The number of actual casualties was inflated in newspaper accounts by several orders of magnitude.

This attack on a civilian target may have turned public opinion against Germany but for the leading circles in France and Britain it was further proof of the Luftwaffe’s destructive power.

General Vuillemin’s visit

In 1938 the head of the French airforce General Vuillemin visited Germany and was taken around to see the rebuilt German airforce.

 

 

Everywhere he went he saw huge numbers of modern aircraft parked at runways. In exhibitions the German planes seems to be much faster than their counterparts in other countries.

During a trip on his transport a new German fighter flew by so fast that it made him feel he was stationary. With planes like these Germany was unstoppable.

What the General didn’t know was that the same planes were taken from airport to airport in order to impress him with their numbers.

As for the model he saw from his plane, it was again a mirage. The German transport pilot had skillfully reduced speed to the absolute limit and the fighter passed by at full speed thus giving the impression of unequaled speed!

When Vuillemin returned to France he warned the country’s leaders that the French airforce would be easily destroyed by the Luftwaffe.

British hawks vs doves

In Britain the elite were split between those who supported appeasement and those who wanted rearmament.

The first group led by Prime Minister Chamberlain believed it was not in British best interests to intervene in Central European affairs and wanted to avoid excessive military spending.

The hawks led by Vansittart, Eden and Churchill wanted to build up the armed forces and especially the RAF in order to counter the expansionist plans of the dictatorships.

Both sides unwittingly supported the German disinformation effort.

The doves presented the threat posed by the Luftwaffe as a reason for avoiding conflict. The hawks overstated Luftwaffe strength in order to force the government into spending more for the military.

The Germans were able to feed disinformation to British officials both through the media but also through a disinformation operation. In the 1930’s the Abwehr had succeeded in identifying the British intelligence officers in Holland and had managed to recruit some of them. At the same time they had a spy inside MI-6.

German officials controlled by the Abwehr became fake British spies and gave manufactured information to the already identified British intelligence officers.

This material was accepted by the Brits since it fitted with their view of a powerful Luftwaffe.

German self-deception

The German propaganda offensive was so successful that even the German leadership was tricked into overestimating the capabilities of the Luftwaffe. In July 1939 Hitler visited a special exhibition of the latest Luftwaffe aircraft at Rechlin airport.

All the models presented were clearly ahead of anything the Allies could field. With these types into production the enemies of the Reich would be easily smashed.

Strengthened by this display of airpower Hitler was ready to risk going to war.

There was just a small problem. All the models presented were research models or were using special equipment that could not be mass produced. Goering was furious at his subordinates for tricking the Fuehrer. In 1942 he said: ‘I once witnessed a display before the war at Rechlin, and compared with that I can only say – what bunglers all our professional magicians are! Because the world has never before and never will again see the likes of what was conjured up before my – and far worse, the Führer’s – eyes at Rechlin!’  

Conclusion

For most of the 1930’s Germany was weak militarily. This weakness should have led the National Socialist party into following a peaceful foreign policy.

Instead the Germans were able to manipulate foreign opinion and give the impression of great military power. Through the skillful use of propaganda and disinformation Britain and France were unable to intervene as their Allies in central Europe were forced to accept Hitler’s demands.

Fearing devastating bomber attacks on their cities foreign leaders were forced to capitulate to Hitler’s demands. At the same time Hitler’s forces were not ready for a serious conflict.

In the end however the German leadership became just as infatuated with the idea of an invincible airforce and Hitler’s decision to risk global war in 1939 may be attributed, in part, to it.

Sources: ‘Intelligence and strategy: selected essays’, ‘Deception: The Invisible War Between the KGB and the CIA’, ‘London calling North Pole’, ‘The War Path: Hitler's Germany 1933-1939’, ‘The right of the line: the Royal Air Force in the European War, 1939-1945’, Wikipedia

Soviet cipher teleprinters of WWII

At the start of the Soviet-German war the cipher machines used by Soviet authorities were the K-37 ‘Crystal’ (a modified Hagelin B-211) and the cipher teleprinters B-4 and M-100.

Few details about these machines are known. I have covered the K-37 here. An article in agentura.ru says that the B-4 was built in the 1930’s and used in Spain during the civil war, in the Far East border incidents with Japan and in the Russo-Finnish war of 1940.

A modernized version of the B-4 called M-100 was built in 1940 and installed in American busses in order to provide mobility (it weighed 141kg). By the summer of 1941 there were 96 sets of the M-100 in service.

In 1943 a more compact version of the M-100 was built and given the designation M-101.

The agentura piece does not give details on the characteristics of these machines.

German interception of Soviet radio-teletype networks

During the 1930’s the SU started to use radio-teletype. Since 1936 the Germans had equipment that automatically intercepted and printed this traffic.

From TICOM reports it seems that the military networks used 2-channel teleprinters while the economic links used multichannel systems.

The 2-channel links employing cipher T/P assigned one channel for the cipher traffic and the other for operator ‘chat’.

There were at least three agencies that intercepted this traffic.

1). The Army Ordnance, Development and Testing Group, Signal Branch Group IV C  -  Wa Pruef 7/IV C at an experimental station in Hillersleben-Staats.

2). The Forschungsamt, an agency reporting directly to Hermann Goering.

3). The Army’s signal intelligence agency OKH/GdNA/In 7/VI (General der Nachrichtenaufklaerung) and its Group VI - OKH/GdNA Group VI.

Forschungsamt success in 1943

In 1943 the Forschungsamt informed the Army agency of their success in reconstructing a Soviet cipher teleprinter used between Moscow and the Fronts. This machine was solved because during every pause seven characters of pure ‘key’ were transmitted. A meeting was held in September 1943 between Councilor Paetzel (head of the FA’s cipher research department), Councilor Kroeger (the FA’s cipher machine specialist) and the Army agency’s Dr Pietsch (head of the mathematical research department) and Doering (head of cipher machine research).

The Soviet machine had 6 wheels. Five enciphered the respective Baudot impulses while the sixth controlled their movement.

The wheels had the following positions (pins):

wheel I – 49

wheel II – 47

wheel III – 46

wheel IV – 45

wheel V – 41

wheel VI – 43

The Soviet scrambler corresponded to the left portion of the German SZ 40/42 cipher attachment. The Forschungsamt people stated that they would build a copy of this machine in order to decrypt this traffic more efficiently.

More details about the Forschungsamt solution of the Soviet cipher teleprinter are given by Bruno Kröger in TICOM reports DF-240 and DF-241. Kröger was the FA’s cipher machine expert and during the war he solved not only the Soviet machine but also the Swiss diplomatic Enigma K.

The Soviet cipher teleprinter was used on 2-channel networks and the FA’s Technical Division was able to build equipment that automatically intercepted and printed this radio traffic. The cipher text was then examined by Kröger’s department and it was discovered that during transmission pauses the Russian letter П was enciphered seven times in succession. Messages interrupted by transmission pauses were examined and their first and last seven characters analyzed in order to uncover the operating principles of the device.

Through this cryptanalytic procedure it was possible to find out that the machine had 6 wheels that stepped regularly, then their pin arrangement was identified and with the daily key recovered all the day’s traffic could be solved.

This success however turned out to be short lived since in late 1943 the Soviet cipher machine was modified and no pure ‘key’ was transmitted during transmission pauses. It seems that from then on this traffic was only examined by the Army’s Inspectorate 7/VI.

Efforts of the Army signal intelligence agency

The Army agency Inspectorate 7/VI assigned its own unit to intercept and evaluate this traffic. This was Group VI operating during 1942-44 from Loetzen, East Prussia.

Unteroffizier Karrenberg, the member of that unit assigned to work on the cipher teleprinter said in postwar interrogations that this traffic was first intercepted in 1940 in Warsaw. However it was not systematically collected and analyzed till summer 1943. They called this traffic ‘Bandwurm’ because of the non-repeating cipher.

There were 8 T/P links from the Army Fronts to Moscow plus 2-3 Airforce links and a link to the Far East command. It was also used by the NKVD. There was no direct T/P link between the individual Front staffs. Instead messages had to be routed through Moscow.

According to Karrenberg the machine had two settings a large and a small. The large setting gave a simple substitution because the wheels did not turn. This was used for operator ‘chat’. The small setting gave an endless column substitution since the wheels moved.

In TICOM report I-153 he says: ‘In Autumn 1944 both the end of 'adder' and every pause in the cipher proper was preceded by seven key letters [redacted]. Then the traffic went off the air and reappeared in December with no external change except that the seven ‘residue' letters had been reduced to three, suggesting a modification of the machine’. In TICOM report I-30 he says that the attachment had 5 small wheels driven by a large one with a period of 43.

These were the same characteristic observed in the machine analyzed by the Forschungsamt. However another OKH cryptanalyst named Buggisch says that the FA machine and the ‘Bandwurm’ were different.

Buggisch was assistant to Doering in the cipher machine research section of Inspectorate 7/VI. In his interrogation TICOM I-64 he says that the cycle of one wheel was 37 and the others 30-80. The machine was analyzed by the mathematics department and a cryptanalyst Troeblicher or Troebliger played a leading part. Thanks to a ‘compromise’ of 8 messages enciphered with the same settings 1.400 characters of pure ‘key’ were recovered. However they were not able to solve the machine because they lacked the manpower.

Unfortunately Buggisch left the OKH agency in June 1944 so he did not know anything more.

The Germans may have failed to solve this machine but they were able to decode messages ‘in depth’ by anagramming. A machine was built that automatically printed the Baudot traffic in Hollerith/IBM cards and these were searched for repeats but with limited success.

The intercepted messages contained reports on Soviet and German military dispositions, statements by POW's, signal intelligence reports, reports for TASS and SOVINFORMBUREAU, letters concerning postings, transfers, promotions, weather situation reports and supply manifests.

Information from the War Diary of Inspectorate 7/VI

More details are available from the monthly reports found in the War Diary of Inspectorate 7/VI.

In July 1943 a report by dr Pietsch says that the examination of Russian Baudot material revealed cipher teleprinter traffic and an effort was made to copy this traffic either by LNA (Leitstelle der Nachrichtenaufklärung in Loetzen) or Staats (Wa Pruef 7/IV C). Processing was to be carried out at Referat 13:

(2) Die eingehende Beobachtung der Baudot-Aufnahmen ergab, daß neben normalen Klar- und Chitexten auch Material anfällt, daß als eigentlicher Fernschreibschlüsselverkehr anzusprechen ist. Es wurden Maßnahmen verabredet, um das Material in einer zur Bearbeitung geeigneten Form (Lochstreifen, Einbeziehung des Verständigungsverkehrs) nach Berlin zu bekommen. Eine tiefergehende Bearbeitung dürfte nur an Ort einer Empfangsstelle (LNA oder Staats) möglich sein. Ob man jedoch beim Fehlen jeder Geräte-Kenntnis über primitive Feststellungen hinauskommen kann, bleibt abzuwarten. Über die weitere Entwicklung wird Referat 13 berichten.

In August ’43 the tapes with the Baudot traffic were examined but investigations could not be carried forwards due to the limited traffic and the many errors due to bad reception.

In September ’43 dr Pietsch and dr Doering (head of Referat 13) met with their Forschungsamt counterparts Councilors Paetzel and Kroeger (the FA’s cipher machine specialist), to discuss the Soviet cipher teleprinter problem.

Investigations continued and in November ’43 the analysts of Referat 13 succeeded in solving a long message and recovering the pure ‘key’:

6. Russischer Baudot--‐Verkehr. Es gelang, für einen längeren Spruch den reinen Schlüssel zu erstellen und damit den Geheimtext zu lösen. Schlussfolgerungen über den Bau und die Wirkungsweise der Schlüsselfernschreibmaschine konnten bisher nicht daraus gezogen werden.

In December ‘43 the departments were renamed, with Referat 13 becoming Referat b2. A second message was solved and investigations continued:

6. Russischer Baudot--‐Verkehr. Aus einem zweiten Spruchmaterial wurde stückweise der reine Schlüssel ermittelt. Weitere Materialen wurden laufend untersucht.

In February and March ’44 departments b1 (general research into cipher machines) and b2 (former 13) worked on the teleprinter problem, examining the Soviet 4-letter and 5-letter Baudot traffic and the movement of the cipher wheels of the device:

Referat b1

3. Russischer Baudot--‐Verkehre: Neu in Angriff genommen wurde die Untersuchung von russischen 4B--‐ und 5B--‐Sprüchen, die in Baudot--‐Fernschreibverkehren auftreten. Die Untersuchungen befinden sich noch im Anfangsstadium.

Referat b2

5. Russischer Baudot--‐Verkehr: Die Untersuchungen über die gegenseitige Abhängigkeit der einzelnen Impulse des reinen Schlüssels wurden an weiterem Spruchmaterial fortgesetzt.

In April ’44 department b1 stated that through analysis of the indicator groups the Soviet Baudot traffic could be subdivided into three distinct groups. The first being probably a cipher machine unlike the second and the third unclear:

 3. Russischer Baudot--‐Verkehre: Durch Kenngruppenuntersuchungen gelang Trennung des Materials in drei Gruppen, von denen die erste im Gegensatz zur zweiten möglicherweise von einer Maschine stammt, während das dritte Verfahren völlig ungeklärt ist.

The report of department b2 shows that there was a meeting at Wa Prüf 7 to better organize the interception of this traffic. Investigations on the recovered pure key continued.

In the following months investigations continued but no breakthrough was achieved. There were complaints about the limited traffic intercepted.

In December ’44 four messages in depth were solved and pure key analyzed:

Russische Baudot verkehre

Aus dem anfallenden material könnte ein kompromiss von 4 phasengleichen sprüchen  gefunden werden, der zum grössten Teil gelöst wurde. Mit Untersuchungen am reinen schlüssel wurde begonnen.

In January ’45 investigations of the recovered pure key continued and in February more in depth messages were solved:

Russische Baudot verkehr

An der lösung weiterer phasengleicher sprüche wurde gearbeitet; ausserdem wurden die untersuchungen am reinen Schlüssel fortgesetzt.

The last report, of March ’45 says that investigations continued:

Russische Baudot verkehr

Die untersuchung der russischen Baudot-verfahren wurde fortgesetzt.

The Poets series cipher machines

In the immediate postwar period the Anglo-Americans were able to solve at least two Soviet cipher teleprinters. These were given the names Coleridge and Longfellow.

Coleridge was used on military networks in the European part of the Soviet Union. By March 1946 it had been solved. The Coleridge decrypts provided important intelligence about the Soviet military’s order of battle, training activities and logistical matters.

The other system, Longfellow, was reconstructed by July 1946 and the settings were first retrieved in February 1947.

It seems both machines were ‘lost’ in 1948 when the Soviets introduced emergency changes in their cryptologic systems.

It is not clear if Coleridge and Longfellow had a connection with the cipher machines that the Germans attacked during the war.

Coleridge may have been the system the Germans called ‘Bandwurm’.

Primary sources:

From TICOM I-2 ‘Interrogation of Dr. Huettenhain and Dr. Fricke at Flenshurg,21 May 1945’, p2

... they also have another machine„ funkfernschreiber, which encodes during transmission. it uses the international five impulse teleprinter code.

Q. Did the Russians use this machine much?

A. It became increasingly important during the last 1 ^1/2 years.

Q. What units used it?

A. Only the highest staffs, press and diplomatic services.

From TICOM DF-240 ‘Characteristics, Analysis and security of cryptographic systems’ - Parts III and IV, p37-39

Both texts indicated the pauses in transmission by - - - - - etc.  The cipher tape has the peculiarity that in passing from the preliminary call-up to the transmission pause, the Russian letter Π, represented in the radio alphabet by + + + + +, occurs seven times.

…………………………………………….

Now since it was natural to assume that in this transition to and from cipher texts the same letter Π= + + + + + likewise appeared seven times in each case but vas no longer recognizable due to the encipherment the first and last seven cipher values of all cipher texts interrupted by transmission pauses were subjected to special study. Since the machine, once the daily key had been set up, was used very frequently during the course of the day for sending cipher text with numerous pauses in transmission without any new daily key being set up, rather numerous fragments of a length of seven letters were available at known intervals of greater or lesser lengths.

…………………………………………….

From this it could be concluded that the first seven and the last seven letters of each secret text came from enciphering the letter Π= + + + + + seven times and hence these fragments of cipher text represented pure key text. The following study of these fragments of pure key text led to a recognition of the fact that the first impulses show the same repeated picture in the chain of plus and minus impulses at an interval of 37, the second impulses at an interval of 39, the third impulses at an interval of 41, the fourth and fifth at an interval of 43 and 45 respectively (the intervals may have been 35, 37, 39, 41, 43). This showed the length of the five cipher wheels and their cam pattern according to the day’s setting. Each cam crest caused the inversion of the plain impulse into its opposite while a cam trough left a plain impulse unchanged. The wheels regularly moved one step after each cipher letter.

With this the decipherment of the cipher text had been accomplished. The reconstruction of the cam pattern of the wheels, which was set up new each day, was easily accomplished.

From TICOM DF-241 ‘The Forschungsamt’- Part I, p25

18. The Russian radio [2-channel] cipher machine with a channel for plain text and a channel for cipher text could be studied after the Technical Division had constructed a receiving device which at the same time removed the scrambling. The five elements of the radio alphabet [bands] ware enciphered singly through five wheels which move evenly. The wheels could be set up new each day corresponding to the daily key; but the period was constant and invariable. It was possible to solve this completely.

From TICOM DF-241 ‘The Forschungsamt’- Part IV, p38

It need only be mentioned here that the 2-channel cipher machine was withdrawn from use a few days after the Forschungsamt succeeded in solving it. When the machine was put into use again some weeks later, the cipher device of the cipher channel had been so altered that solution by the previous method was no longer possible since, when switching the machine from procedure traffic to cipher text and between a pause in transmission and cipher text, the switching became effective at once and the idling period of 7 elements had dropped out. That the same machine was involved was proven only by the receiver device which still broke up the scrambled text into a clear and a cipher text in the same manner as before. Because OKH had great interest in this traffic and its own receivers did not work perfectly, and because further detailed work at this time (Autumn 1943) in the Forschungsamt was not possible, OKH received all new traffic on this machine for processing. 

From TICOM I-30 ‘Report on Interrogation of  Uffz. Karrenberg  at Steeple Claydon on 7th July 1945 at 11.00 am’, p2

The subject of this interrogation was confined to Karrenberg’s work on Russian Baudot letter ‘strip’, traffic known to the Germans as ‘BANDWURM’ and not to be confused with Russian 5-letter, traffic also carried on Baudot lines.

The Germans had not captured any of the apparatus used but considered that it consisted of two parts: 1) a Baudot-teleprinter with the letters of the Russian alphabet (excluding q and 'g') and figure and letter shift making 32 characters in all; 2) a cipher attachment consisting of 5 small wheels driven by one large wheel.

Each of the small wheels had a pattern of positive and negative impulses and each wheel worked in conjunction with one of the five impulses produced by pressing a key of the teleprinter, the effect being to add a positive or negative impulse to each of the five impulses produced by the letter being sent. This in effect means adding a letter of key to the clear letter to produce a cipher letter.

Depths were frequent on the traffic intercepted by the Germans, but they do not seem to have made any attempt to reconstruct the wheel patterns. In the case of the driving wheel they came to the tentative conclusion that it had a period of 43. The preambles of messages were always enciphered which resulted in stereotyped and known beginnings to messages. The machine setting for a message was indicated by means of a two figure number which presumably referred to a table of settings; a different table was used each day.

Before the actual start of a message a passage of operator's chat was sent enciphered by the addition of a constant letter to each letter of the clear text. This letter was then sent en clair- and repeated three times. The object of this was to see that the receiver had his machine net up correctly.

The system was used by the Army and Air Force and to a lesser extent by the N.K.W.D.

From  TICOM I-153 ‘Second Interrogation of Uffz. Karrenberg of OKH on the Baudot-Scrambler Machine (Bandwurm)’, p2

P.W. stated that he believed the ‘Bandwurm’ traffic was first intercepted in 1940 in Warsaw. As far as he had been able to make out no interest had then been taken in it. The first actual knowledge we had of a traffic with the same external features (chat. indicators, eto.) was in summer 1943 when the first real interest was taken in it and the traffic was sent to Berlin for analysis. He understood that it went to a Dr. Pietsch and Doering.

There were a number of links usually varying according to the number of armies (Frontstaebe). The maximum number was 8. One end of each link was always in Moscow, the other would be mobile, and move with the armies. There were also one or two Airforce links. There was also supposed to be a link with the Far East. Traffic was heavier from the ‘outstations’ to Moscow.

and page 3

In Autumn 1944 both the end of 'adder' and every pause in the cipher proper was preceded by seven key letters [redacted]. Then the traffic went off the air and reappeared in December with no external change except that the seven ‘residue' letters had been reduced to three, suggesting a modification of the machine. In general it is clear that some of the features of the key at least have not changed in the last nine months.

From TICOM I-64 ‘Answers by Wm. Buggisch of OKH/Chi to Questions sent by TICOM’ , p2-3

1. Russian Systems 

In 1943 B heard that the Forschungsamt (no individual names given) had claimed some success on a Russian teletype machine, and had re-created the action of the machine. It was a machine with a very long cycle being not prime but the product of several smaller cycles--like the SZ42. B. did not know the cycle of all of the individual wheels or any other details. He heard this from DOERING, who was then doing his research on the T-52, but liaison with the FA was bad anyway (Major Mettig was particularly opposed to the SS taint) and the next he heard was that the traffic found by the FA had stopped. B. remembered only that the cycle of one wheel was 37; the others, he thought, varied widely from 30-80.

Late in 1943 and increasingly in 1944 OKH itself began to intercept non-Morse, 5-impulse traffic (called ‘Hughes’ by B.). The Mathematics Referat went to work on it, with TROEBLICHER playing a leading part. At the end of 1943 the Russians created a ‘kompromiss’, giving a depth of about 8 messages with the same setting. With this they were able to recover 1400 letters of pure key and at the same time to ascertain that the traffic being passed was the 5-figure code, with regular station chat enciphered at the same time on the machine (Suggests a machine in constant motion as described by Karrenberg).Part of the depth was created within the same long message, so that the machine had a cycle, at least in this one case of about 1450 letters. The actual number was thought to be very significant by the Germans, as it was prime and so could not be the product of smaller cycles in any way that they could imagine. This differentiated it from the machine which the FA had broken. The Germans postulated either a single tape machine like the T43 or a machine in which the motions of the wheels influenced each other,1 and 2 affecting 3, 3 affecting 5, etc. as in the T52. They were never able to prove one theory or the other. (B. apologized for this. Said they did not have enough mathematicians to tackle the fascinating problem of determining what the motion must be to create this cycle. Seemed quite convinced that there would be a unique solution to the problem.) After this experience they devised Hollerith machinery to locate depths, but in fact they only found three or four more cases and none of these gave additional cycle evidence or even furnished as much pure key as the first one. B. left the section in June 1944. He thinks the traffic slumped off in the summer of 1944 and LNA took steps to try to improve the reception, as they believed the traffic was still there. TROEBLICHER was detailed to this end of the work at this time. B. stressed one fact which had surprised him, that they had never had information about either of these machines (he assumed that the one the FA broke was not the same because of the difference on cycles.) from PW or agent sources.

B. said in passing that their own security idea on the subject of wheel machines of this sort was that the cycle should not be the product of smaller periods(as in Hagelin) even if this was long. Mutual influence of wheels should be used to avoid this, but at the same time care must be taken that too short a period was not created in the process. This in fact had apparently been done by the Russians, but the fact that it was not repeated suggested to him that they might have seen the weakness and corrected it.

Troeblicher is mentioned in CSDIC (U.K.) SIR 1717, appendix A as Troebliger (Uffz). He worked in Group IV, Referat 1b as an analyst on Russian Baudot traffic.

Sources: CSDIC (U.K.) SIR 1717, SI-32 ‘Special intelligence report’,  ‘European Axis Signal Intelligence in World War II’ vol2 and vol4, TICOM reports I-2, I-64, DF-98, I-30, I-153, I-169, I-173, DF-240, DF-241, ‘The Secret Sentry: The Untold History of the National Security Agency’, Intelligence and National Security article: ‘Behind Venona: American signals intelligence in the early cold war’, Soviet cryptographic service 1920-1940 , Kriegstagebuch Inspectorate 7/VI

TICOM reports I-2, I-64, DF-98, DF-240, DF-241 can be found in my TICOM folder, reports I-30, I-153, I-169, I-173 can be downloaded from TICOM Archive.

Acknowledgments: It was Frode Weierud who first pointed to me the German interest in the Soviet teleprinter and the characteristics of the machine solved by the Forschungsamt in 1943. Credit also goes to Randy Rezabek for finding and uploading to the internet the interrogations of Karrenberg since they contain lots of information on the cipher machine.