Showing posts with label Agents codes. Show all posts
Showing posts with label Agents codes. Show all posts

Monday, February 2, 2026

The compromise of Polish diplomatic, intelligence service and resistance movement communications 1930’s-1945

 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).

The activities of the Polish government departments and intelligence agencies attracted the attention of both Germany and the USA and UK and their codebreakers were able to solve most of the Polish cipher systems.

Saturday, October 7, 2017

The Communist agents cipher solved by the Forschungsamt

In the recently released TICOM report DF-240 ‘Characteristics, Analysis and security of cryptographic systems’ there is a short description of a cryptosystem used by communist agents:



It is interesting that the names mentioned in the example are Harri Meier, Theodor Felder, Albert Schwarz, Max Hamburger and Karl Gutmann. 



Monday, August 1, 2016

The US military attaché double transposition cipher


Apart from the standard cryptosystems (Military Intelligence Code, War Department Confidential Code. M-138-A strip cipher) US attaches also had an emergency double transposition cipher. According to the instructions for this system, found in the files of Pers Z (decryption department of the German Foreign Ministry) (2):

Use of cipher. To enable M/As to exchange safely secret or confidential messages with other attaches or with assistants or agents acting under their direction, the double transposition cipher is prescribed.

Keys. The keys will be determined by the M/A. They will consist of short phrases consisting of from five to twenty letters. They will be changed at frequent intervals.





However the same numerical sequence was used for both cages, which means that this system would have been vulnerable to cryptanalysis.

Monday, April 18, 2016

The ciphers of Czechoslovakia’s government in exile

At the end of the First World War the multiethnic Austro-Hungarian Empire collapsed and out of its ruins emerged several new countries. One of these was Czechoslovakia, containing the Czech areas of Bohemia and Moravia together with Slovakia and Carpathian Ruthenia in the east.

In the interwar period Czechoslovakia followed a foreign policy supportive of France and was part of the Little Entente. The country had a stable democracy and its industrial resources were large (based on the Skoda works) for such a small country. However there were two important problems affecting Czech national security. On the one hand the rise of Nazi Germany and its rearmament was a clear security threat. At the same time there were serious problems with the German and Slovak minorities that resented Czech rule.

Czechoslovakia contained a large number of minorities that were dissatisfied with the ruling Czech establishment. Especially the German minority made up roughly 23% of the population (according to the 1921 census) and a large part of it was concentrated in the border with Germany called Sudetenland. Many of the Sudeten Germans wanted for their areas to be unified with Germany and in the 1930’s Hitler’s Germany supported the demands of the Sudeten German Party. These claims were rejected by the Czech government of Edvard Beneš and as the Czech crisis threatened Europe with a new war a conference took place in Munich between the governments of Germany, Italy, Britain and France.  

Without support from Britain and France the Czech government was forced to cede the Sudeten territories to Germany and also lost other disputed areas to Hungary and Poland. Even though Germany had succeeded in absorbing the Sudeten areas and in weakening Czechoslovakia that did not stop Hitler’s offensive plans and in March 1939 German troops invaded and occupied the rest of the country. From then on the country was ruled by Germany and special attention was given to its heavy industry which produced weapons for the German armed forces.

During the war the Czechoslovak Government in Exile, headed by Beneš, was based in London and had regular communications with the Czech resistance and with its diplomatic missions and intelligence service stations abroad. In order to protect these communications several cryptosystems were used by the Czech crypto department.

Information on these systems is available from books and articles written recently:

1). The books Odhalena tajemstvi šifrovacich kličů minulosti, Gentlemani (ne)čtou cizi dopisy and Válka šifer. Výhry a prohry československé vojenské rozvědky (1939-1945) by Jiri Janecek have descriptions of the ciphers and the author’s conclusion was that the security afforded by these systems was limited.

2). A series of articles written for ‘Crypto World’ by Jozef Kollár describe each cipher system, explain how to encipher and decipher and also evaluate their security. The articles are:

Cipher ‘TTS’ (double transposition of the text followed by letter to figure substitution)

Cipher ’Rimska dva’ (letter to figure substitution followed by double transposition of the digits)

Cipher ‘Rimska osem’ (homophonic letter to figure substitution followed by encipherment with repeating 10-figure additive sequence)

Cipher ‘Rimska devat’ (letter to figure substitution followed by additive encipherment, repeating additive created from a passphrase)

Cipher ‘Rimska desat’ (letter to figure substitution followed by transposition then additive encipherment, repeating additive created from a passphrase, passphrase is also used to limit the cells of the transposition table)

Cipher ‘Rimska trinast’ (transposition of the text followed by polyalphabetic substitution)

Cipher ‘Eva’ (transposition of the text using a pyramid shaped transposition table)

Cipher ‘Marta’ (letter to figure substitution followed by additive encipherment, additive created via passphrase autoclave procedure)

Cipher ‘Ruzena’ (letter to figure substitution followed by additive encipherment, additive created via passphrase procedure)

Cipher ‘Utility’ (letter to figure substitution followed by transposition)

Cipher ‘Palacky’ (letter to figure substitution followed by additive encipherment, additive created via passphrase procedure, cipher digits multiplied by a constant)

Compromise of Czech ciphers

The Czech resistance movement and the Czech intelligence service caused serious problems for the German authorities with their most audacious operation being the assassination of Reinhard Heydrich, protector of Bohemia and Moravia and former head of the Reich Main Security Office. However after this episode the Germans took many security measures and were generally able to keep the resistance activities under control. Keeping the Czech areas pacified was particularly important since Czechoslovakia had a developed heavy industry sector which produced weapons for the German armed forces.

In their counterintelligence operations the Germans benefitted from having the ability to read a substantial amount of the traffic exchanged between the Czech IS in Britain and the Czech resistance in the occupied territories. This case has been covered in detail in Svetova Revoluce and the codes of the Czechoslovak resistance.

Report on the compromise of the communications of the government in exile

After the end of WWII it seems that the Czechoslovak authorities learned from POW interrogations about the compromise of their ciphers. Karol Cigáň, who worked in the Defense Ministry’s cipher department, summarized some of this information in a report written in 1989.

The report ‘Dopady lúštenia šifrovacieho systému čs. londýnskeho MNO z rokov 1940-1945 na domáci odboj’, can be found in the archive of the Museum of the Slovak National Uprising in Banská Bystrica and in the Central Military Archive at Prague.



In the report Cigan analyzed the Czechoslovak STP cipher and found it insecure. In addition he proved the compromise of Czechoslovak ciphers by examining reports from the office of the high ranking SS official Karl Hermann Frank.

A report from November 1944 had a summary of Funkwabwehr (Radio Defense) operations and it said that during the previous month 8 radio links, whose cipher procedures could be solved, were kept under observation. Of special interest was traffic between the Protectorate and London regarding the preparations for the uprising.

In the month of October a total of 488 messages were solved and 8 cipher keys derived for the STP cipher.



In pages 37-41 Cigan directly compared the Funkawbehr decodes with some of the Czechoslovak telegrams found in the country’s national archives.

For example messages exchanged between the Minister of National Defense General Ingr and Ján Golian and Jaroslav Krátký in the Protectorate and with Heliodor Píka in Moscow. 



The author’s conclusion was that the use of insecure ciphers during wartime played an important role in undermining the operations of the Czechoslovak resistance movement and these events should be acknowledged by the country’s historians. 

Acknowledgments: I have to thank Jozef Krajcovic for his help in locating the report ‘Dopady lúštenia šifrovacieho systému čs. londýnskeho MNO z rokov 1940-1945 na domáci odboj’ and Štefan Porubský for informing me of the articles from Crypto World. 

Sunday, August 2, 2015

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.

Monday, July 6, 2015

Operation Overlord and the secret messages of the BBC

During WWII resistance movements in German occupied Europe were organized and supported by the British intelligence services SIS and SOE. Messages to their agents in Europe were sometimes transmitted through the radio program of the British Broadcasting Corporation. Agents were told to listen to the BBC at a specific time and wait for a prearranged message whose meaning would be known only to them.

For example:


The German intelligence agencies however knew of this arrangement and through their agents in the Resistance were able to learn of the meaning of some of these messages. In the run up to the Normandy invasion, the Germans were able to deduce from the BBC‘s messages that the Allied invasion was imminent and that the Resistance had been given orders to attack the German forces in France.



Source: British national archives HW 40/76 ‘Enemy exploitation of SIS and SOE codes and cyphers: miscellaneous reports and correspondence’

Wednesday, April 1, 2015

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. From September '43 messages of the line 6003 London-Nice are continuously decoded (6).

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 (7) 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 (8):





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). 'KODY WOJNY. Niemiecki wywiad elektroniczny w latach 1907–1945', p735
(7). British national archives HW 40/222
(8). 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’.

Thursday, January 15, 2015

The wartime adventures of Prince Max Hohenlohe

During WWII the military forces of the Allies and the Axis battled in Europe and Asia but behind the scenes there were efforts to negotiate some sort of compromise peace. These efforts however never amounted to much since both sides distrusted each other and the military situation made it clear that the Allies could win the war through military force alone.  

Since the 1930’s a segment of German society that opposed the National-Socialist regime had tried to establish contact with foreign countries in order to topple Hitler. During the war the same groups contacted US and British officials in neutral countries and tried to gain their support in order to remove the NS regime from power. The Western Allies were aware of these efforts but they did not offer material support to the members of the German resistance.
At the same time elements of the NS regime came to realize that the war was lost and thus made cautious attempts to contact Allied officials that could promote some sort of compromise peace. Heinrich Himmler was leader of the SS security service and thus one of the most powerful men in Nazi Germany. Yet by 1943 he was beginning to realize that hopes for a successful conclusion of the war were slim. His subordinate General Walter Schellenberg, head of the foreign intelligence department of the Sicherheitsdienst, had many talks with Himmler on the need for a compromise peace and in 1943 he was able to make the first attempts at contacting Allied officials.
The Germans knew that Allen Dulles was in charge of the OSS-Office of Strategic Services station in Bern, Switzerland and they chose to contact him through people associated with the German resistance.
In early 1943 Prince Max Hohenlohe (working on behalf of the Sicherheitsdienst) was given permission to travel to Switzerland and meet Dulles. Unfortunately it doesn’t seem like their meeting remained a secret for long. In the Finnish national archives one can find the decoded version of message No 2.181 of April 7, 1943, giving an overview of their discussion.


 
The original is available from the US National Archives and Records Administration - collection RG 59.



Both the German resistance (through Admiral Canaris) and the Sicherheitsdienst (through Schellenberg) had warned Dulles that his communications were compromised but it doesn’t seem like he acted on this information. These efforts for a compromise peace were probably doomed from the start (especially since the Germans seemed to have overestimated the influence of Dulles) but even so without secure communications the talks could not have remained secret for long.

Tuesday, January 6, 2015

Unanswered questions of WWII cryptology – progress report

Back in 2013 I wrote down several cases of WWII cryptologic history that require more research. Since then I’ve spent a lot of time and money trying to find new information. Has the effort paid off? Let’s have a look at each case:

1). US State Department strip cipher
I wrote: How bad was the compromise of the State Department’s high level system? That question is hard to answer because there is limited information available and it doesn’t seem like the Americans were really interested in learning the full extent of the compromise. Some documents that would shed more light on this affair are proving very hard to find…

It is clear that Germans, Japanese and Finns were able to solve many alphabet strips both circular and special and thus read State Department messages from embassies in Europe and Asia. The most important intercepted messages seem to have been those from Bern, Switzerland and Chungking, China.

Unfortunately several important reports are still classified by the NSA and we have to wait for the declassification procedure. At the same time I haven’t been able to track down the Carlson-Goldsberry report, detailing the Finnish solution of the State Department strip cipher. This report was written in late 1944 by two US cryptanalysts after interviewing Finnish codebreakers in Sweden. 
Another aspect of this case concerns the messages from the OSS - Office of Strategic Services and OWI - Office of War Information stations in Bern that were also sent via diplomatic channels. It’s not clear why these messages were sent using State department codes and not through their own systems. In this area information is lacking, since the OSS organization doesn’t seem to have officially acknowledged the compromise of their communications during the war.

2). NKVD 5th Department codebreakers
During WWII the Soviet Union invested significant resources in the interception and exploitation of enemy radio traffic. The internal security service NKVD and the Army’s general staff had codebreaking departments with the former recruiting many talented mathematicians. According to author Matthew Aid  ‘By the end of World War II, the 5th Directorate controlled the single largest concentration of mathematicians and linguists in the Soviet Union.’

So far very limited information is available regarding their war time efforts versus foreign codes (not only Axis but also US, UK and those of neutral countries).

 3). Referat Vauck success
In the period 1942-44 the German Army’s signal intelligence agency Inspectorate 7/VI had a separate deparment (Referat 12) assigned with the solution of the encoded messages of Allied spy groups operating in occupied Europe. Head of the department was dr Wilhelm Vauck, so his unit was also called Referat Vauck. In 1944 they were transferred to the OKW radio defense department so their reports can no longer be found in the files of Inspectorate 7/VI.

I had written about this case: How successful were they during the war? Unfortunately we do not know. The relevant file in the British national archives HW 40/76 ‘Enemy exploitation of SIS and SOE codes and cyphers’ says that postwar files have been retained and my request for the release of the interrogations of dr Vauck has been rejected by the archives staff
Thankfully I‘ve been able to track down the monthly reports of Referat 12 for the period April ’42-February ’44 and I will be writing an essay on them.

An interesting discovery, made while I was trying to find information on Referat Vauck, was that OKW/Chi was also solving Allied agents codes during the war (with significant success it seems). Not much is known about this aspect of OKW/Chi operations…

4). Forschungsamt information
Goering’s Forschungsamt was one of the main German codebreaking/intelligence agencies of the period 1939-45, yet a detailed history of that organization still eludes us. This is another case where it’s up to the NSA to declassify the relevant documents, written by Forschungsamt personnel in the 1950’s.

5). German Enigma investigations
Several authors claim that the Germans never suspected that their Enigma cipher machine was solved by the Allies and that they considered it to be unbreakable.

I had written: The Germans constantly evaluated the security of their Enigma cipher machine. There were many studies on whether the daily key or parts of it could be retrieved through cryptanalysis. Those studies are the TICOM DF-190 to DF-190AN files…..More research is needed to evaluate the German methods and the way they influenced their security measures.
Since then I’ve posted information on case ‘Wicher’ (Polish solution of the Enigma) showing that the Germans knew the device had been compromised in the prewar period and in 1943 they got information from the US regarding the solution of their naval version.  So far it’s clear that the German Navy’s codebreakers found a solution for their 4-rotor machine in late ’44 but we don’t know much about the similar work of the Army cryptanalysts. More research is needed in this case.

6). Japanese Purple and Coral cipher machines
Were the Germans able to solve the cipher machines used by the Japanese foreign ministry and by Japanese military attaches?

I wrote: PURPLE was solved by American and Soviet codebreakers. Did the Germans have any success with it? Until recently the answer was no. 
However it seems there is more to this story.

The Coral machine was used by military attaches and the Anglo-Americans solved it in 1944. In the same year dr Steinberg of the German Army’s signal intelligence agency was transferred to OKW/Chi where he worked on a cipher machine used by the Japanese attaché. Did he manage to solve it? 
TICOM report I-64 ‘Answers by Wm. Buggisch of OKH/Chi to Questions sent by TICOM’ says ‘B. thinks Steinberg (of 209 fame) solved some Jap machine traffic which was difficult but not so hard as Enigma. B. thinks it was traffic of the Jap Military Attache.’

There is scattered information that points towards the solution of an important Japanese code or cipher machine in the period 1943/44 but no conclusive evidence. Maybe more information will become available in the future.

7). Soviet diplomatic code
I wrote: The Soviet Union used a code enciphered with one time pads as its main diplomatic system during WWII. This system if used correctly is unbreakable. 

Were the Germans able to read parts of this traffic? There are some strange statements in Allied and German reports…
The recently declassified TICOM report DF-111 ‘Comments on various cryptologic matters’ by Adolf Paschke (head of the linguistic cryptanalysis group in the German foreign ministry’s decryption department) says that in the years 1927-30 parts of the Soviet diplomatic traffic could be read since the additive pads were sometimes used twice if the message was long enough. Paschke had also identified the use of the same additive tables more than once in some links. Regarding wartime traffic he says that they couldn’t solve any since there were no repetitions but in the report he also added cryptically that Russian material of the Forschungsamt and the High Command’s deciphering department OKW/Chi were destroyed in 1943 during a bombing attack on Berlin.

Although the Germans might have not solved any Soviet diplomatic traffic they did succeed in solving Comintern communications.

8). M-209 decoding device
I wrote: I’m surprised that no one has figured out how this machine worked!

I have to say I’m still surprised that this device has not received any attention from historians and/or the media!