More information on the compromise of Polish codes in WWII

1). In The codes of the Polish Intelligence network in occupied France 1943-44 I’ve added:

Update: German decodes of the London-Grenoble traffic can be found in pages 793-877 of ‘KODY WOJNY. Niemiecki wywiad elektroniczny w latach 1907–1945’. They date from July 1943 to October 1944 and are signed ‘Szef II Oddzialu Sztabu’, ‘Marian’, ‘Alfred’, ‘Szef Ekspozytury II Oddzialu Sztabu’, ‘Lubicz’, ‘Vox’, ‘Los’, ‘Rawa’, ‘Klemens’, ‘Major Zychon’, ‘Mikolaj’, ‘Bernard’, ‘Biz’, ‘Zenon’.

2). In Polish Stencil codes and secret agent ‘’Knopf’’ I’ve added:

Update: German decodes of the Bern-London traffic can be found in pages 878-916 of ‘KODY WOJNY. Niemiecki wywiad elektroniczny w latach 1907–1945’. They date from October 1942 to September 1944 and are signed ‘Szef II Oddzialu Sztabu’, ‘Darek’, ‘Gano’, ‘Hugo’, ‘Mak’, ‘Orkan’, ‘Espe’, ‘Jerzy’

Intelligence operations in Switzerland - Hans von Pescatore, Captain Choynacki and General Barnwell R. Legge

In WWII Poland fought on the side of the Allies and suffered for it since it was the first country occupied by Nazi Germany. In the period 1940-45 the Polish Government in Exile and its military forces contributed to the Allied cause by taking part in multiple campaigns of war. Polish pilots fought for the RAF during the Battle of Britain, Polish troops fought in N.Africa, Italy and Western Europe and the Polish intelligence service operated in occupied Europe and even had agents inside the German High Command. 

Although it is not widely known the Polish intelligence service had spy networks operating throughout Europe and the Middle East. The Poles established their own spy networks and also cooperated with foreign agencies such as Britain’s Secret Intelligence Service and Special Operations Executive, the American Office of Strategic Services and even the Japanese intelligence service. During the war the Poles supplied roughly 80.000 reports to the British intelligence services (1), including information on the German V-weapons (V-1 cruise missile and V-2 rocket) and reports from the German High Command (though the agent ‘Knopf’) (2). In occupied France the intelligence department of the Polish Army’s General Staff organized several resistance/intelligence groups tasked not only with obtaining information on the German units but also  with evacuating Polish men so they could serve in the Armed Forces (3).

Compromise of Polish codes

Poland’s role in WWII is well known, especially the success of Marian Rejewski, Henryk Zygalski and Jerzy Różycki during the 1930’s in solving the Enigma cipher machine, used by the German Armed forces. It is important to note that countries with large cryptologic staffs such as France and Britain had not managed to solve this device, in that time period.

Although the Poles were successful in the offence they neglected their defense. Their diplomatic, military attaché, resistance movement and intelligence service codes were read by the Germans during the war. Especially important for the Germans was the solution of the cipher used by Major Szczesny Choynacki, Polish deputy consul in Bern, Switzerland.

The telegrams of Major Choynacki

Choynacki regularly communicated with the Polish intelligence service in London and transmitted valuable reports from his agents/contacts in Switzerland and throughout occupied Europe. 

His cryptosystem consisted of an enciphered codebook. The codebook contained 4-figure groups and was enciphered with a version of the British Stencil Subtractor Frame. The codebreakers of the Signal Intelligence Agency of the Supreme Command of the Armed Forces - OKW/Chi (Oberkommando der Wehrmacht/Chiffrier Abteilung) were able to solve this system in late 1942-early 1943 and from then on his voluminous traffic to London was continuously decoded (4).

Details about the content of these messages are available from the postwar interrogations of German intelligence officers, specifically Willy Piert and Hans Von Pescatore (5). They were both members of the German Legation in Bern and they conducted intelligence operations against the Allied agencies and even the Swiss IS.

The decoded messages revealed that Choynacki had well placed agents numbered in the 500 series.

According to the Germans the most damaging agent was No 594, Isidore Koppelmann, a Jewish banker living in Basel. One of Choynacki’s decoded messages was used to uncover his identity.

It is up to historians to research this case further and identify the full extent of the damage caused to the Polish networks from the compromise of their communications.

The German spy in the US embassy and the messages of General Legge

Another interesting German operation, mentioned in the interrogations of Piert and Pescatore, was one directed against the US embassy in Bern, Switzerland. In 1941 the Germans were able to recruit a Swiss national who worked in the US embassy. This person, named Fuerst, had access to the office of the US military attaché General Barnwell R. Legge and he was able to take documents plus the used carbon paper and give it to the Germans. These documents revealed some of Legge’s sources:

Although Fuerst was apprehended in March 1942 the information he provided, coupled with decodes of US traffic (6), gave the Germans an insight into the sources and operations of the US intelligence agencies.

Notes:

(1). Journal of U.S. Intelligence Studies article: ‘England's Poles in the Game: WWII Intelligence Cooperation’

(2). War in History article: ‘Penetrating Hitler's High Command: Anglo-Polish HUMINT, 1939-1945’

(3). ‘War Secrets in the Ether’, p230-1

(4). Polish Stencil codes and secret agent ‘’Knopf’’, Major Choynacki’s Ace: the Solution to an Old Puzzle of Wartime Intelligence, KV 2/1329 ‘Willy PIERT / Hans Von PESCATORE’

(5). KV 2/1329 ‘Willy PIERT / Hans Von PESCATORE’

(6). The compromise of the communications of General Barnwell R. Legge, US military attache to Switzerland

Acknowledgments: The credit for locating the very interesting Piert/Pescatore report goes to Craig McKay, author of Major Choynacki’s Ace: the Solution to an Old Puzzle of Wartime Intelligence.

Book review - The triumph of Zygalski's sheets: the Polish Enigma in the early 1940

The solution of the German Enigma cipher machine by the codebreakers of Bletchley Park and the effect that this had on World War II became public knowledge in the 1970’s, with the publication of books like ‘The Ultra Secret’. Since then hardly a year goes by without a new book or movie coming out and claiming that the British codebreakers basically won WWII all on their own. Unfortunately the work of the Polish codebreakers has not received the same recognition, even though they were the first to solve Enigma messages in the 1930’s.

In the interwar period Poland had to face the hostility of a weakened Germany and a rising Soviet Union. The Polish military authorities knew that they had to keep a close eye their dangerous neighbors, so they built up an efficient codebreaking service, called Biuro Szyfrów. The Polish codebreakers played an important role during the Polish-Soviet War of 1919–21 by solving the ciphers used by the Red Army and learning of the enemy plans in advance.

Against Germany the department faced a serious problem due to the introduction of the Enigma machine in the late 1920’s. The solution of this device required scientific research undertaken by mathematicians and for this reason the department hired Marian Rejewski, Henryk Zygalski and Jerzy Różycki. Using material provided by the French intelligence service, the three of them were able to solve the Enigma in the early 1930’s.

Enigma Press has published a new book on Henryk Zygalski, called ‘The triumph of Zygalski's sheets: the Polish Enigma in the early 1940’ by Zdzisław J. Kapera.

The author has used Zygalski’s personal diary in order to reconstruct his work in Poland and then France plus he has included rare photographs from the archive of Anna Zygalska-Cannon.

The book covers Zygalski’s work for the Polish cipher bureau in the 1930’s, their evacuation to France in 1939, the solution of current Enigma traffic in 1940 (together with the British codebreakers) and his work for the signal intelligence service of Vichy France at PC Cadix. The last two chapters cover his escape to the UK (due to the German occupation of Vichy in late 1942), his assignment to the Polish radio intelligence unit near Stanmore and his postwar academic career at the University of Surrey.

The author has given particular attention to Zygalski’s cryptanalytic technique for the solution of Enigma traffic (Zygalski sheets) and he has also taken a look into why the intelligence gained from the Enigma did not play an important role during the fighting in Norway and France.

Overall this is a valuable contribution to Enigma historiography.

Q&A with Zdzisław J. Kapera

The author was kind enough to answer some of my questions.

1). Can you give a summary of Enigma Press and the books you’ve published?

The Enigma Press is a scholarly publisher from Cracow - Mogilany. The Enigma Bulletin is one of series/journals printed irregularly and in limited number of copies maximum 150. Contents of the Enigma Bulletin you can find at the end of my book. We have also a Polish series of pamphlets on the Enigma story, but only two issues appeared, one being an introduction to the machine and the second is a brief biography of Rejewski. 

2). In the book you say that you consider Zygalski a personal hero. Can you expand on that and also explain what new information you were able to discover while researching this book?

I have always been thinking that besides Rejewski Zygalski should be presented in the full light. His sheets saved possibility to read Enigma after changes in January 1939. The British were unable to use them despite producing the full set of sheets (60 necessary copies) in November and December 1939. In my book I reconstructed from all available sources the turn of events in autumn and winter 1939/1940. I used the Polish, French and British sources together and compared them for the first time. Turing learned from Zygalski in mid January 1940 and the British also had an opportunity to read more and more. Without the period January to May 15, 1940 the British would start reading regularly Enigma many months later. Even if Enigma did not save Norway and France in this crucial period the British were able to put foundations for ULTRA.  

3). What is the current state of cryptologic historiography in Poland? Is there renewed interest in the accomplishments of the Polish codebreakers?

Very few people are now interested in the Enigma story as sources are very scattered. We expect that young historian Lukasz Ulatowski will write a history of the Polish Cipher Bureau in the 1920 and 1930s. 

4). What other topics do you plan to research for future books?

I am now working on the dangerous moment, the spring of 1940, when the reading the Enigma would be nearly exposed. Stupidity of some military committee of the Polish Government in Exile because of useless political revenge would help the Germans to discover reading Enigma. I plan to publish a pamphlet on the escape of the Polish cryptanalysts from the Vichy Cadix radio intelligence center and on the efforts of the Germans to protect Enigma against the WICHER operation. 

Allied agents codes and Referat 12

In the course of WWII both the Allies and the Axis powers were able to gain information of great value from reading their enemies secret communications. In Britain the codebreakers of Bletchley Park solved several enemy systems with the most important ones being the German Enigma and Tunny cipher machines and the Italian C-38m. Codebreaking played a role in the Battle of the Atlantic, the North Africa Campaign and the Normandy invasion. 

In the United States the Army and Navy codebreakers solved many Japanese cryptosystems and used this advantage in battle. The great victory at Midway would probably not have been possible if the Americans had not solved the Japanese Navy’s JN25 code.

On the other side of the hill the codebreakers of Germany, Japan, Italy and Finland also solved many important enemy cryptosystems both military and diplomatic. The German codebreakers could eavesdrop on the radio-telephone conversations of Franklin Roosevelt and Winston Churchill, they could decode the messages of the British and US Navies during their convoy operations in the Atlantic and together with the Japanese and Finns they could solve State Department messages (both low and high level)  from embassies around the world.

Radio intelligence and codebreaking played an important role not only in the military and diplomatic fields but also in the shadow war between the Allied intelligence agencies, the European Resistance movements and the German security services. In the period 1939-41 German troops conquered most of continental Europe and the occupied countries were forced to contribute to the Axis effort by sending raw materials, agricultural products and forced labor to Germany. Thanks to the blockade of German occupied Europe by the Royal Navy and the harsh demands of the German authorities life in the occupied areas was bleak. Discontent over German occupation led many people to join resistance movements and oppose the authorities, either by printing and distributing anti-Axis leaflets and books, by sabotaging war production or by directly attacking the German troops and their collaborators in the government and the civil service.

The codes of the Polish Intelligence network in occupied France 1943-44

In WWII Poland fought on the side of the Allies and suffered for it since it was the first country occupied by Nazi Germany. In the period 1940-45 the Polish Government in Exile and its military forces contributed to the Allied cause by taking part in multiple campaigns of war. Polish pilots fought for the RAF during the Battle of Britain, Polish troops fought in N.Africa, Italy and Western Europe and the Polish intelligence service operated in occupied Europe and even had agents inside the German High Command.

Although it is not widely known the Polish intelligence service had spy networks operating throughout Europe and the Middle East. The Poles established their own spy networks and also cooperated with foreign agencies such as Britain’s Secret Intelligence Service and Special Operations Executive, the American Office of Strategic Services and even the Japanese intelligence service. During the war the Poles supplied roughly 80.000 reports to the British intelligence services (1), including information on the German V-weapons (V-1 cruise missile and V-2 rocket) and reports from the German High Command (though the agent ‘Knopf’) (2).

In occupied France the intelligence department of the Polish Army’s General Staff organized several resistance/intelligence groups tasked not only with obtaining information on the German units but also  with evacuating Polish men so they could serve in the Armed Forces. These networks obviously attracted the attention of the German security services and in 1941 the large INTERALLIE network, controlled by Roman Czerniawski, was dismantled.

Another large network was controlled by Zdzislaw Piatkiewicz aka ‘Lubicz'. The book ‘Secret History of MI6: 1909-1949’, p529 says about this group: ‘Some of the Polish networks were very productive. One based in the south of France run by ‘Lubicz' (Zdzislaw Piatkiewicz) had 159 agents, helpers and couriers, who in August and September 1943 provided 481 reports, of which P.5 circulated 346. Dunderdale's other organizations were rather smaller’.

From German and British reports it seems that the radio communications of the Polish spy groups in France (including the ‘Lubicz' net) were compromised in the period 1943-44. Wilhelm Flicke who worked in the intercept department of OKW/Chi (decryption department of the High Command of the Armed Forces) says in ‘War Secrets in the Ether’ (3):

The Polish intelligence service in France had the following tasks:

1. Spotting concentrations of the Germany army, air force and navy.

2. Transport by land and sea and naval movements.

3. Ammunition dumps; coastal fortifications, especially on the French coast after the occupation of Northern France.

4. Selection of targets for air attack.

5. Ascertaining and reporting everything which demanded immediate action by the military command.

6. Details regarding the French armament industry working for Germany, with reports on new weapons and planes.

The Poles carried on their work from southern France which had not been occupied by the Germans. Beginning in September 1942 it was certain that Polish agent stations were located in the immediate vicinity of the higher staffs of the French armistice army.

In March 1943 German counterintelligence was able to deal the Polish organization a serious blow but after a few weeks it revived, following a reorganization. Beginning the summer of 1943 messages could be read. They contained military and economic information. The Poles in southern France worked as an independent group and received instructions from England, partly by courier, and partly by radio. They collaborated closely with the staff of General Giraud in North Africa and with American intelligence service in Lisbon. Official French couriers traveling between Vichy and Lisbon were used, with or without their knowledge, to carry reports (in the form of microfilm concealed in the covers of books).

The Poles had a special organization to check on German rail traffic to France. It watched traffic at the following frontier points: Trier, Aachen, Saarbrucken, München-Gladbach, Strassburg-Mülhausen and Belfort. They also watched the Rhine crossings at Duisburg, Coblenz, Düsseldorf, Küln, Mannheim, Mainz, Ludwigshafen, and Wiesbaden. Ten transmitters were used for the purpose.

All the Polish organizations in France were directed by General Julius Kleeberg. They worked primarily against Germany and in three fields:

1. Espionage and intelligence;

2. Smuggling (personnel);

3. Courier service.

Head of the "smuggling service" until 1.6.1944 was the celebrated Colonel Jaklicz, followed later by Lt. Colonel Goralski. Jaklicz tried to penetrate all Polish organizations and send all available man power via Spain to England for service in the Polish Army.  The "courier net" in France served the "Civil Delegation", the smuggling net, and the espionage service by forwarding reports. The function of the Civil Sector of the "Civil Delegation" in France was to prepare the Poles in France to fight for an independent Poland by setting up action groups, to combat Communism among the Poles, and to fight against the occupying Germans. The tasks of the military sector of the Delegation were to organize groups with military training to carry on sabotage, to take part in the invasion, and to recruit Poles for military service on "D-Day". The "Civil Delegation" was particularly concerned with Poles in the German O.T. (Organisation Todt) or in the armed forces. It sought to set up cells which would encourage desertion and to supply information.

Early in 1944 this spy net shifted to Northern France and the Channel Coast. The Poles sought to camouflage this development by sending their messages from the Grenoble area and permitting transmitters in Northern France to send only occasional operational chatter. The center asked primarily for reports and figures on German troops, tanks and planes, the production of parts in France, strength at airfields, fuel deliveries from Germany, French police, constabulary, concentration camps and control offices, as well as rocket aircraft, rocket bombs and unmanned aircraft.

In February 1944 the Germans found that Polish agents were getting very important information by tapping the army telephone cable in Avignon.

In March 1944, the Germans made a successful raid and obtained important radio and cryptographic material. Quite a few agents were arrested and the structure of the organization was fully revealed.

Beginning early in June, increased activity of Polish radio agents in France became noticeable. They covered German control points and tried to report currently all troop movements. German counterintelligence was able to clarify the organization, its members, and its activity, by reading some 3,000 intercepted messages in connection with traffic analysis. With the aid of the Security Police preparations were made for the action "Fichte" which was carried out on 13 July 1944 and netted over 300 prisoners in all parts of France.

This, together with preliminary and simultaneous actions, affected:

1. The intelligence service of the Polish II Section,

2. The smuggling service,

3. The courier service with its wide ramifications.

The importance of the work of the Poles in France is indicated by the fact that in May 1944 Lubicz and two agents were commended by persons very high in the Allied command "because their work was beginning to surpass first class French sources." These agents had supplied the plans of all German defense installations in French territory and valuable details regarding weapons and special devices.

Flicke’s statements on the solution of Polish intelligence codes in 1943 can be confirmed, in part, by the postwar interrogation of Oscar Reile, head of Abwehr counterintelligence in occupied France. In his report 'Notes on Leitstelle III West Fur Frontaufklarung' (4) he said about the Polish intelligence communications:

CODE-CRACKING BY FUNKABWEHR

107. Leitstelle III West also benefited from the work done by the code and cipher department of Funkabwehr, which studied all captured documents connected with codes and ciphers, with the object of decoding and deciphering the WT traffic of agents who were regarded as important and could not be captured. 

108. Valuable results were often obtained by Funkabwehr. During the winter of 43/44, the above-mentioned code and cipher department succeeded in breaking codes used by one of the most important transmitters of the Polish Intelligence Service in FRANCE. For months thereafter WT reports from Polish agents to ENGLAND were intercepted and understood; the same applied to orders they received from ENGLAND. The Germans also learnt that important military plants were known to the Allies, and a considerable number of names and cover names of members of the Polish Intelligence Service were discovered.

Flicke also said ‘Early in 1944 this spy net shifted to Northern France and the Channel Coast. The Poles sought to camouflage this development by sending their messages from the Grenoble area and permitting transmitters in Northern France to send only occasional operational chatter’. This statement can also be confirmed by other German and British reports.

The monthly reports of Referat 12 (Agents section) of the German Army’s signal intelligence agency OKH/In 7/VI (5) mention spy messages from Grenoble in May and July 1943 as links top and 71c (9559, Grenoble), so it is possible that these are the Polish intelligence messages that Flicke says were solved in summer 1943. Unfortunately these reports are difficult to interpret since they use codewords for each spy case.

More information is available from messages found in the captured archives of OKW/Chi (since Chi also worked on Polish military intelligence codes). The British report DS/24/1556 of October 1945 (6) shows that messages on the link London-Grenoble were solved and these were enciphered with the military attaché cipher POLDI 4.

The same report mentions that in August 1944 the British authorities became aware that decoded Polish military intelligence messages from Grenoble were sent from Berlin to the Abwehr station in Madrid, Spain:

‘In August 1944, a series of decoded Polish ‘Deuxieme Bureau’ messages between London and Grenoble were seen by us in ISK traffic being forwarded by Berlin to Abwehr authorities at Madrid. The time lags varied between 5 and 43 days. S.L.C. Section at headquarters informed us that this was a properly controlled leakage, and that no cypher security action was necessary or desirable.’

Some of these messages can be found in the British national archives (7):

It is interesting to note that the response of the higher authorities was ‘this was a properly controlled leakage, and that no cypher security action was necessary or desirable’, without however giving more details.

Conclusion

During WWII the Polish intelligence service operated throughout Europe and was able to gather information of great value for the Western Allies. These activities were opposed by the security services of Nazi Germany and in this shadow war many Allied spy networks were destroyed and their operatives imprisoned or killed. In their operations against Allied agents the Germans relied not only on their own counterintelligence personnel but also signals intelligence and codebreaking. Fixed and mobile stations of the Radio Defense Corps (Funkabwehr) monitored unauthorized radio transmissions and through direction finding located their exact whereabouts.

The Agents section of Inspectorate 7/VI and OKW/Chi analyzed and decoded enciphered agents messages, with the results passed to the security services Abwehr and Sicherheitsdienst. Both agencies solved Polish intelligence communications including traffic from Switzerland, France, Poland, the Middle East and other areas. The Polish intelligence networks in France were an important target for the Germans not only because they were a security risk but also because they would undoubtedly assist the Allied troops in their invasion of Western Europe in 1944. In that sense the compromise of the communications of the Polish military intelligence network was an important success since it allowed the Germans to dismantle parts of this group and also learn of what the Allied authorities wanted to know about German strengths and dispositions in France.

According to Flicke the success started in summer 1943 and from the British reports we can see that they continued to solve the traffic till summer ’44 (when France was liberated). It is not clear of when the Brits first learned that the Polish communications had been compromised and what measures they took to prevent the leakage of sensitive information. It is also not clear of whether they chose to inform the Poles about all this…

Notes:

(1). Journal of U.S. Intelligence Studies article: ‘England's Poles in the Game: WWII Intelligence Cooperation’

(2). War in History article: ‘Penetrating Hitler's High Command: Anglo-Polish HUMINT, 1939-1945’

(3). ‘War Secrets in the Ether’, p230-1

(4). CSDIC SIR 1719 - 'Notes on Leitstelle III West Fur Frontaufklarung', p15

(5). War Diary of OKH/In 7/VI - May and July 1943

(6). British national archives HW 40/222

(7). British national archives HW 40/221

Sources: ‘Secret History of MI6: 1909-1949’, Journal of U.S. Intelligence Studies article: ‘England's Poles in the Game: WWII Intelligence Cooperation’, ‘War Secrets in the Ether’, CSDIC SIR 1719 - 'Notes on Leitstelle III West Fur Frontaufklarung', HW 40/221 ‘Poland: reports and correspondence relating to the security of Polish communications’, HW 40/222 ‘Poland: reports and correspondence relating to the security of Polish communications’, War in History article: ‘Penetrating Hitler's High Command: Anglo-Polish HUMINT, 1939-1945’, War Diary of OKH/In 7/VI

Update: German decodes of the London-Grenoble traffic can be found in pages 793-877 of ‘KODY WOJNY. Niemiecki wywiad elektroniczny w latach 1907–1945’. They date from July 1943 to October 1944 and are signed ‘Szef II Oddzialu Sztabu’, ‘Marian’, ‘Alfred’, ‘Szef Ekspozytury II Oddzialu Sztabu’, ‘Lubicz’, ‘Vox’, ‘Los’, ‘Rawa’, ‘Klemens’, ‘Major Zychon’, ‘Mikolaj’, ‘Bernard’, ‘Biz’, ‘Zenon’.

Compromise of Polish communications in WWII – an overview

In WWII Poland fought on the side of the Allies and suffered for it since it was the first country occupied by Nazi Germany. At the end of the war the suffering of the Poles did not end since they had to endure the Soviet occupation of their country and the installation of a communist regime. 

The betrayal of Poland by its Western Allies was a hard blow, especially since its armed forces fought bravely in multiple campaigns. Polish pilots fought for the RAF during the Battle of Britain, Polish troops fought in N.Africa, Italy and Western Europe, the Polish intelligence service operated in occupied Europe and even had agents inside the German high command. Finally the Poles had managed to solve the German Enigma cipher machine in the 1930’s and when they shared the details of their solution with British and French officials in July 1939 they helped them avoid a costly and time consuming theoretical attack on the Enigma.

Considering this impressive success of the Polish cipher bureau one would expect that Polish codes would have a high standard of security and that Polish military, diplomatic and intelligence communications would be secure from eavesdroppers. Surprisingly this was not the case. Even though the Poles periodically upgraded their cipher systems it was possible both for the Germans and the Anglo-Americans to read some of their most secret messages.

1). The main Polish diplomatic codes were read in the prewar period and in the years 1940-42.

2). The code used by the Polish resistance movement for communications with the London based Government in Exile was read by the Germans since 1942 (by the agents section of OKH/In 7/VI).

3). The code of the Polish intelligence service in occupied France was solved in 1943 and messages of the ‘Lubicz’ network were read. The book ‘Secret History of MI6: 1909-1949’, p529 says about this group: ‘Some of the Polish networks were very productive. One based in the south of France run by ‘Lubicz' (Zdzislaw Piatkiewicz) had 159 agents, helpers and couriers, who in August and September 1943 provided 481 reports, of which P.5 circulated 346. Dunderdale's other organizations were rather smaller’.

I’m going to cover this case in the future.

4). Polish diplomatic/military attache communications on the link Washington-London seem to have been read by the Germans and the British. A German intelligence officer named Zetzsche said in TICOM report I-159 ‘Report on GAF Intelligence based on Interrogation of Hauptmann Zetzsche’, p3

‘Intelligence concerning foreign diplomatic exchanges was received from the Forschungsamt (subordinated directly to GOERING) through Ic/Luftwesen/Abwehr, and was given a restricted distribution. It consisted of intercepted Allied radio-telegrams (e.g. London-Stockholm), ordinary radio reports (e.g. Atlantic Radio) and intercepted traffic between diplomats and ministers on certain links, e.g. Ankara-Moscow (Turks), Bern-Washington (Americans), London-Washington (Poles).

10. The last-mentioned source was of great value before and during the invasion and after the breaking-off of Turkish-German relations. In general the Forschungsamt reports contained a great deal of significant information concerning economic and political matters.’

The British also read this traffic as can be seen from messages like the following:

 

5). Polish intelligence/military attaché messages from the Middle East and Bern, Switzerland were read by the Germans throughout the war. For example:

 

Unfortunately there is limited information available on these cases and some very interesting TICOM reports have not been declassified by the NSA yet. Once they are released I will be able to rewrite these essays.

German special intelligence, the M-138 strip cipher and unrest in India

Signals intelligence and codebreaking played an important role in WWII. British and American codebreakers solved many important Axis crypto systems, such as the German Enigma machine and the Japanese Navy’s code JN25. Similarly the codebreakers of the Axis nations also had their own victories versus Allied codes.

One of the most important Allied cryptosystems compromised by the codebreakers of Germany, Finland and Japan was the State Department’s M-138-A strip cipher.  This cipher system was used for important messages by US embassies around the world and also by the Office of Strategic Services and the Office of War Information.

Unfortunately accurate information on the compromise of this system is limited and the statements made in some of the available TICOM reports are often contradictory. Still it is clear that from 1940 till late 1944 the Axis codebreakers were able to read a lot of the traffic sent on the ‘circular’ and ‘special’ strips.

In complicated cases like this one the only way to find more information is by checking all the available sources. During WWII there was an exchange of information between Germany, Finland and Japan on the State Department’s strip cipher. Some of these messages were intercepted and decoded by the Western Allies, so it is possible to track the progress of the Axis codebreakers through their decoded messages.

Professor Wolfgang Franz and OKW/Chi’s mathematical research department

Nazi Germany had several codebreaking agencies both military and civilian. The armed forces had separate agencies for the Army, Navy and Airforce plus there were codebreaking departments in the Foreign Ministry, in Goering’s Forschungsamt and in the Supreme Command of the Armed Forces. This last department operated on civilian lines even though it was subordinated to the military.

The OKW/Chi agency

OKW/Chi - Oberkommando der Wehrmacht/Chiffrier Abteilung was the Signal Intelligence Agency of the Supreme Command of the Armed Forces. It had been established as a separate agency in 1920 and in the interwar period it was able to solve the codes of many foreign countries. Initially the focus was on philological research but the introduction of more complex codes and ciphers led the Germans to invest in mathematical research in the field of cryptanalysis.

The person who orchestrated this change in priorities was Wilhelm Fenner. Fenner started working for the department in 1921 together with his friend Fedor Novopaschenny, a former Tsarist codebreaker and in 1922 became an official employee. In the beginning he didn’t know much about solving codes but he learned mathematical techniques from his Russian friend and came to realize that the agency would need to make organizational changes in order to solve the more difficult foreign cryptosystems.

Since Fenner quickly became head of the cryptanalysis department he was able to carry out his plan to reorganize the agency. First he introduced a more rigorous training program for analysts and concentrated on the scientific analysis of cryptologic history and systems.

The next step in the 1930’s was to hire mathematicians.

Professor Huettenhain and OKW/Chi’s mathematical research department

The first mathematician hired by Fenner was Erich Huettenhain. In the mid 1930’s Huettenhain worked at the observatory of the University of Münster and came to Fenner’s attention when he contacted Chi with some of his proposals for cryptographic systems. Although his systems were ‘unusable without exception’ he was offered a job at Chi and he accepted.

Huettenhain became responsible for mathematical analysis of more difficult cipher systems and in the early years of WWII new personnel were hired to form a separate mathematical research department.

These were Wolfgang Franz, Werner Weber, Ernst Witt, Georg Aumann, Alexander Aigner, Oswald Teichmueller and Johann Friedrich Schultze.

 

During the war they solved several difficult foreign cipher systems. Weber was successful with a Japanese diplomatic code transposed on a stencil, Witt solved the stencil subtractor frame used by the Polish diplomatic and intelligence service and Franz was responsible for the exploitation of the State Department’s strip cipher.

Apart from the aforementioned individuals, two more mathematicians, Karl Stein and Gisbert Hasenjaeger were hired to work in the cipher security department.

Professors Franz and the State Department’s strip cipher

According to the recently declassified TICOM report DF-176 ‘Answers written by professor doctor Wolfgang Franz to questions of ASA Europe’ Wolfgang Franz primarily studied mathematics in the period 1924-1929, during 1930-1934 worked as an assistant at the mathematical seminar at the University of Marburg and in 1937 moved to the University of Giessen as an assistant. When at the beginning of WWII the University of Giessen was closed down he spent a semester as a substitute at the University of Gottingen.

Franz’s area of expertise was topology.

Thanks to a friend of his who knew Huettenhain he was able to get assigned to the OKW Cipher department in Berlin in 1940. The initial training program consisted of solving simple codes and ciphers and as Franz was easily able to cope with these he moved on to real traffic.

The first systems he worked on were a Mexican and a Greek code and he was able to solve them. The most important system solved by Franz was the US diplomatic M-138-A strip cipher, called Am10 by the Germans:

‘Especially laborious and difficult work was connected with an American system which, judging by all indications was of great importance. This was the strip cipher system of the American diplomatic service which was subsequently solved in part.’

According to DF-176, p6 Franz had started his own investigations into this system and was able to make some limited progress when he received the ‘circular’ strips 0-1 and three ‘special’ strips used between Washington and Helsinki, Tallinn and Reval. Using these strips messages could be solved and his investigations could move forward.

 

Thanks to the success of the department is solving the strip cipher dr Huettenhain was able to hire more mathematicians and expand the research section.

Regarding the strip cipher 70 ‘different traffics’ (links?) were identified and 28 solved plus 6 numerical keys.

 

It is interesting to note that a special cryptanalytic device called the ‘Tower-Clock’ was used to solve the strip system. Franz says in pages 9-10:

‘In addition, there was built at my suggestion at the Bureau an electric machine which permits determining a number of repetitions of letters in a polyalphabetic substitution on a width of 30 with a depth of 20 to 80 lines, taking one line at a time, which naturally is fundamental for problem (f) above.’

According to EASI vol2 ‘Notes on German High level Cryptography and Cryptanalysis’   , p56-57               

c. Statistical "depth-increaser." - The "Turmuhr," or "Tower-Clock  was a device for testing a sequence of thirty consecutive cipher letters statistically against a given "depth" of similar sequences, to determine whether the former belonged to the given depth. It was used "primarily for work on the U.S. strip cipher, when cribbing which was generally employed was impossible. It cost approximately $1,000.00.

The apparatus consisted of a single teleprinter tape reading head (speed 1 1/2 symbols per second); a storage means, by which any one of five different scores could be assigned, on a basis of frequency, to each of the letters in the 30 separate monoalphabets that resulted from the 30 columns of depth; a distributor that rotated in synchronism with the tape stepping, and selected which set of 30 scores was to be used as basis for evaluating the successive cipher letters; and a pen recording device.

The German codebreakers were only able to exploit the strip cipher to such a degree thanks to serious mistakes in the use of the system by the State Department. Franz acknowledged this in page 6 of the DF-176 report:

‘This strip cipher system, when rightly employed, doubtlessly has great advantages .It appears to me, however, that it was not used with sufficient caution. Only through carelessness, in part through lack of care in setting up, was it possible to break into the system as far as we did. Only after the Americans had obviously noticed that many of their messages were being read was the application so modified that although the basic idea was the same the possibilities of breaking in were materially reduced.’  

Postwar career

In the postwar period professor Franz returned to teaching at Frankfurt University where he eventually became dean of the newly established Department of Mathematics. Also in 1967 he became president of the German Mathematical Society.

In the end It might give some comfort to the Americans to know that their strip cipher was solved by a real gentleman, as report DF-176 says: ‘Personal contact with Dr Franz indicated that he was a gentleman of unusual scholarship and integrity, an impression confirmed by the report’.

Sources: TICOM reports DF-187 A-G and DF-176, ‘European Axis Signal Intelligence in World War II’ vol2