NSA releases TICOM material to the US National Archives

According to an NSA press release:

More than 29,000 pages of declassified material related to the World War II-era Target Intelligence Committee (TICOM) are now publicly available following a recent transfer from the National Security Agency to the National Archives and Records Administration.

It was NSA’s final transfer of its material related to TICOM, a joint project that began in 1944 between the United States and the United Kingdom. The now-famous “Monuments Men” searched for precious works of art that had been looted by the Nazis with the goal of returning items to their rightful owners. In contrast, TICOM teams followed Allied armies into occupied areas of Western Europe to seize material and equipment Axis powers used for code-breaking and code-making, including the German Enigma cipher. The teams also tried to determine how successful the Germans had been in breaking Allied codes. Through these efforts, the United States and the United Kingdom aimed to read more of the encrypted communications of retreating Nazi armies and better protect their own information from German eavesdropping.

The declassified material is housed at the Archives II facility in College Park, Md. More information about how to locate records held by the National Archives is available at https://catalog.archives.gov/id/5957379.

Information about the National Security Agency is available at www.nsa.gov.

A list of all the files is available from NARA’s website. There are a lot of interesting files, for example:

7131N, Interrogation of Kapitan von Baumbach, Head of OKM/III from 1942-1944 [(U) INTERROGATION OF CAPTAIN VON BAUMBACH]

7252 PAJ Interrogation Report - Comdr. Hashimoto and Lt. Fuji (No TICOM REF #)

7254 PAJ Interrogation Report - Rear Admiral Nomura; Capt. Morikawa; Comdr. Ozawa (No TICOM #)

10663N PAJ Interrogation Report on MAX (Parts 1 - 7) TICOM IF 118a-g

2778 Misc., Data on the Soviet Union (C-1190) [TICOM DF-242 DATA ON THE SOVIET UNION (TRANSLATION OF GERMANY DOCUMENT) ]

2781 Soviet Subversive Activities Against Germany [TICOM DF-288 SOVIET SUBVERSEIVE ACTIVITIES AGAINST GERMANY (TRANSLATION OF GREMAN DOCUMENT) ]

2841 Report on Cipher Device #40 (S-4219 to 4133) [TICOM DF-200A-D REPORTS ON CIPHER DIVICE 40 (TRANSLATION OF GERMAN DOCUMENT) ]

2847 The Russian Cipher Device - K37 (5-4146) [TICOM DF-217 RUSSIAN CIPHER DEVICE K-37 (TRANSLATION OF GERMAN DOCUMENT) ]

2855 The French Cipher Machine, C-36 (Hagelin) (5-4190) [TICOM DF-247B ON FRENCH CIPHER MACHINE C-36 (HAGELIN) (TRANSLATION OF GREMAN DOCUMENT) ]

2986 Regulations for Staff Cryptologic Service in the Red Army (5-3740) [TICOM DF-96 REGULATIONS FOR STAFF CRYPTOLOGIC SERVICE IN THE RED ARMY (TRANSLATION OF GERMAN DOCUMENT) ]

2988 Encipherment of OKK6 (Russian) (5-3742) [TICOM DF-97 ENCIPHERMENT OF OKK6 (TRANSLATION OF GREMAN DOCUMENT WITH PHOTOGRAPHIC PRINTS AND NEGATIVES) ]

3005 Russian Map Keys - 1944 to March 1945 (5-3821) [TICOM DF-131 RUSSIAN MAP KEYS USED 1944 [MARCH 1945] (TRANSLATION OF GERMAN DOCUMENT) ]

3343 Japanese Special Intelligence (SIGINT) Organization [TICOM REPORT ON JAPENESE SPECIAL INTELLEGENCE (SIGINT) ORGANIZATION ]

3419 Report on Japanese Cryptologic and cryptanalytic Operations [TICOM REPORTS ON JAPENESE CRYPTOLOGIC AND CRYPTANALYTIC OPERATIONS ]

5098 Finnish Monthly Reports on Russian Naval Message to 1944 [CIPHERT SURVEY # 17M (NAVAL MESSAGES) COPY OF TICOM DOCUMENT 542 AND TRANSLATIONS ]

5573 Allied Keys to 1938 [FILES DEALING WITH BRITISH, FRENCH AND DANNISH CODES AND CIPHERS ON ALLIEED KEYS TO 1938]

5608 Mathematical Notes on Polish equipment Encipherment [TRANSLATION OF ARTICLE ENTITLED "MATHEMATICAL NOTES ON THE POLISH ENCIPHERMENT" ]

5654 Observation on French Diplomatic Style [TRANSLATION OF OBSERVATION ON FRENCH DIPLOMATIC STYLE]

5781 Dettman: Conclusion [TICOM DF-181 TRANSLATION OF DETTERMAN CONCLUSION ]

6604 TICOM Team Activity in Far East - 1945 (Folder 1 of 5) [JAPANESE TICOM #1-4 REPORTS OF 7 SEPTEMBER 1945, UNITED STATES TICOM TEAMS ACTIVITY REPORTS]

7007 Analysis & Evaluation of the Japanese Intelligence service and It’s Affect on United States Signal security [TICOM S-2 ANALYSIS AND EVALUATION OF JAPANESE INTELLIGENCE SERVICE AND EFFECT ON U.S. SIGNAL SECURITY]

7212 The Development of Russian Cryptographic Systems [TICOM DF-94 TRANSLATION OF TICOM DOCUMENT 2765, DEVELOPMENT OF RUSSIAN CRYPTOGRAPHIC SYSTEMS]

7723 Survey of Czech Systems - 1945-1949 [TICOM DF-189, TRANSLATION OF SURVEY OF CZECH SYSTEMS 1945-1949]

7762 Correspondence Re: Allied Keys May 1941 - July 1942 [TICOM 515 COPY OF CORRESPONDENCE RELATED TO ALLIED KEYS, MAY 1941 TO JULY 1942]

7765 German Studies Allied Ciphers June 1941 - June 1942 (Folder 1 of 2) [TICOM 517 COPY OF GERMAN STUDIES OF U.S. AND BRITISH CIPHERS, JUNE 1941 - APRIL 1943]

7773 Procedure Used in Breaking Turkish Diplomatic Traffic [TICOM 2258 DF-12 REVISED, COPY OF PERCEDURE USED IN BREAKING TURKISH DIPLOMATIC TRAFFIC]

8125 Czech Diplomatic Messages and Decrypts [COPY OF CZECH LANGUAGE DIPLOMATIC MESSAGE AND DECRYPTS 1920 - 1921]

8143 Reports on Interrogations of Japanese Former Cryptanalysts [INTERROGTAION REPORTS OF EIGHT FORMER JAPANESE CRYPTANALYSIS]

8532 German Deciphering 5-LTR TRF between Tokyo and European Capitals [TICOM 2533 COPY OF GERMAN DECIPHERING ATTEMPTS OF FIVE-LETTER TRAFFIC BETWEEN TOKYO AND EUROPEAN CAPITALS]

8747 German - Vierling (Feuerstein) Library/Laboratory 1946-1952 [TICOM M-1 REPORT ON DR. VIERLING'S LABORATORY AT EBERMANNSTADT AND LIBRARY PAPERS, 1946-1952 ]

8774 Jap Cryptographic Worksheets MA Systems 1934-1939 [TICOM 18, COPIES OF GERMAN WORKSHEETS ON JAPANESE MACHINE SYSTEM 48, 1934 - 1939]

8775 Chinese Diplomatic Code and Translations [TICOM 4 COPY OF CHINESE DIPLOMATIC DECODES AND TRANSLATIONS, 1944 - 1945]

8919 Solution of the M-209 Hagelin Machine [TICOM 1-35A COPY OF SOLUTION IF THE M-209 HAGELIN MACHINE]

10168 Reports on the Solution of the Russian Cipher Procedure "Misteriya" [REPORT ON THE SOLUTION OF THE RUSSIAN CIPHER PROCEDURE "MISTERIYA" ]

10349 German Cryptanalysis on American Cryptographic Systems [TICOM NOTE 23: COPY OF BRIEF SURVEY OF THE CRYPTANALYSIS OF AMERICAN CRYPTOGRAPHIC SYSTEMS BY THE GERMAN CRYPTANALYTIC SERVICE DURING WORLD WAR II]

10955 Scientific Writings from Pers Z Archives [TICOM DOCUMENTS #376, COPY OF SCIENTIFIC WRITINGS FROM PERS Z ARCHIVES, DECEMBER 7, 1942]

11099 Finnish Working on Various Russian Codes (S-8778) [COPY OF FINNISH WORKINGS ON VARIOUS RUSSIAN CODES]

12551 German Intelligence and Insight from Working on Radio Traffic of the Soviet Air Force [TICOM DOCUMENT OKL 483 COPY OF GERMAN INTELLIGENCE AND INSIGHT FROM WORKING ON RADIO TRAFFIC OF THE SOVIET AIR FORCE ]

18732 Fills in the History of Russian Diplomatic Systems [TICOM DOCUMENT 1035 COPY OF FILLS IN THE HISTORY OF RUSSIAN DIPLOMATIC AND COMMERCIAL SYSTEMS, 1929 - 1935]

24474 TICOM - "Feuerstein" Technical Project Reports - 1945 (Folder 1 of 4) [DETAILED FEUERSTEIN TECHNICAL PROJECT REPORT]

32957 French/Polish Radio Traffic Regulations in Event of War [TICOM NO.T 3624 FRENCH/POLISH RADIO TRAFFIC REGULATIONS IN EVENT OF WAR ]

44405 Red Army Field Post Listing - Captured German Document 1944 [FIELD POST NUMBERS OF THE RED ARMY]

46891 Pythagoras - Italian Diplomatic Code (Folder 1 of 2) [TICOM DOCUMENT NO. 250, COPY OF PYTHAGORAS, JULY 1936-1939]

46893 TCIOM No. 3293 Berichte Der Grouppe F (Folder 1 of 3) [TICOM DOCUMENT NO. 

3293 COPY OF BERICHTE DER GRUPPE F]

47114 Berichte Uber Den Stand Der Entzifferungsarbeiten April 1916 - October 1918 [BERICHTE UBER DEN STAND DER ENTZIFFERUNGSARBEITEN APRIL 1916 - OCTOBER 1918]

6964 Glossary of German Cryptanalytic Terms [TICOM REPORT I-117: GLOSSARY OF GERMAN CRYPTANALYTIC TERMS ]

10160 State Department Reports on German Foreign Office [TICOM REPORT IF-266: DEPARTMENT OF STATE REPORTS ON THE GERMAN FOREIGN OFFICE (COPY OF STATE DEPARTMENT REPORTS) ]

Update

I added information and pics in New developments in the strip cipher case.

I also made a correction. I had written that the strips 60-1 were used for intercommunication between Bern, London, Lisbon, Algiers and Washington in 1943 but this is not clearly stated in the list. 

Only strips 60-3 and 60-5 were definitely used for intercommunication between the aforementioned embassies. 

Einzeldarstellungen aus dem Gebiet der Kryptologie - Hüttenhain’s statements on the State Department’s strip cipher

During WWII the US State Department used several cryptosystems in order to protect its radio communications from the Axis powers. The main systems used were the unenciphered Gray and Brown codebooks along with the enciphered codes A1, B1, C1, D1 and the new M-138 strip cipher. 

In the period 1940-1944 German, Japanese and Finnish codebreakers could solve State Department messages (both low and high level) from embassies around the world. The M-138-A strip cipher was the State Department’s high level system and it was used extensively during that period. Although we still don’t know the full story the information available points to a serious compromise both of the circular traffic (Washington to all embassies) and special traffic (Washington to specific embassy). In this area there was cooperation between Germany, Japan and Finland. The German success was made possible thanks to alphabet strips and key lists they received from the Japanese in 1941 and these were passed on by the Germans to their Finnish allies in 1942. The Finnish codebreakers solved several diplomatic links in that year and in 1943 started sharing their findings with the Japanese. German and Finnish codebreakers cooperated in the solution of the strips during the war, with visits of personnel to each country. The Axis codebreakers took advantage of mistakes in the use of the strip cipher by the State Department’s cipher unit.

Erich Hüttenhain, who was the chief cryptanalyst of OKW/Chi (Signal Intelligence Agency of the Supreme Command, Armed Forces), said in his unpublished manuscript ‘Einzeldarstellungen aus dem Gebiet der Kryptologie’, p20-21 about the strip system:

IV. Das amerikanische streifenverfahren

Im  2. Weltkrieg benutzten die USA bis September 1944 in Diplomatie, Heer, Luftwaffe und Marine neben anderen Verfahren ein unter dem Namen “Streifenverfahren" bekanntes Chiffrierverfahren.

Des Diplomaten—Streifenverfahren war das aufwendigste und mit den meisten Variations möglichkeiten versehen. Deshalb soll hier nur auf dieses Verfahren eingegangen werden.

Des Streifenverfahren in der Diplomatie war ein Chiffrierverfahren für den Linienverkehr; es bestand aber die Möglichkeit, von der Zentrale aus cq-Sprüche abzusetzen.
Fast jede US-Vertretung im Ausland hat zum chiffrierten Verkehr mit Washington einen Satz von 50 Stäben, auf denen je ein anderes verwürfeltes Alphabet zweimal hintereinander aufgezeichnet war. Täglich wurden 25 dieser Stäbe ausgewählt und in vorgeschriebener Reihenfolge zum Schlüsseln benutzt: Tagesschlüssel.

Nach einigen Monaten wurde der ganze Satz von 50 Stäben gegen einen anderen  satz von 50 Stäben ausgetauscht. Außerdem hatte jede Vertretung des US-Außenministeriums noch einen Stabsatz zur Entschlüsselung von cq-meldungen aus Washington. Auch dieser cq-Satz wurde von Zeit zu Zeit ausgewechselt.

Vom Standpunkt der Kryptologie war dieses Streifenverfahren ein mehrfach belegter Spaltencäsar.

Bald nach dem Beginn der Untersuchungen dieses Chiffrierverfahrens gelang es, die Periode von 25 zu erkennen. Es gelang auch, einige besonders lange Geheimtexte wenigstens teilweise zu entziffern. Es wäre eine harte und langwierige Arbeit geworden, wenn nicht besondere Umstände hinzugekommen wären. Einer dieser umstände war die Tatsache, daß die USA den bei einer Stelle abgelösten Stabsatz an anderer Stelle wieder einsetzten, anstatt ihn außer Kraft zu setzen.

Ein zweiter für die Entzifferung günstiger Umstand war, daß es wegen der U-Boot-Blockade nicht immer gelang, den auszuwechselnden Stabsatz rechtzeitig an alle Außenstellen zu bringen.  In solchen Fällen wurde z.B. ein cq-Spruch an die Stelle, bei der der neue cq-Stabsatz noch nicht eingetroffen war, mit dem bei der Stelle vorhandenen und seit längerer Zeit in Benutzung befindlichen Spezial-Stabsatz verschlüsselt.

Wenn nun dieses Spezial-Verfahren gelöst war, - und das war in der Regel der Fall — so war der Klartext des cq-Spruches bekannt, und es lag ein Klar-Geheim-Kompromiß im neuen cq-Verfahren vor, aus dem die Stäbe des neuen cq-Verfahrens rekonstruiert wurden.

Auf diese Weise wurden von 1942 bis September 1944 insgesamt 22 verschiedene Linien und alle cq-Sprüche mitgelesen.

Aus dieser erfolgreichen EntzifferungsArbeit muß gefolgert werden:

1. Es ist unzulässig, bereits einmal verwendete Schlüssel an anderen Stellen wieder zu verwenden.

2. Es ist nicht zulässig, Chiffrierverfahren einzusetzen‚ die gegen Klar-Geheim-Kompromisse anfällig sind.

Google translation with corrections by Frode Weierud:

IV. The American strip cipher system

During the Second World War and until September 1944, the United States used, together other cipher procedures, an encryption system in its Diplomatic Service, Army, Air Force and Navy that was known as the "Strip procedure."

The diplomatic strip system was the most elaborate and equipped with the most variation possibilities. That is why we will concentrate only on this procedure.

The strip procedure in the diplomatic service was an encryption system for regular, scheduled services; but it also allowed for sending broadcast messages from headquarters.

Almost every U.S. mission abroad had a set of 50 strips for encrypted traffic with Washington, on each of which a different scrambled alphabet was recorded twice in succession. Daily 25 of these rods were selected and used in a prescribed order for ciphering: the daily key.

After a few months the whole set of 50 strips was replaced by another set of 50 strips. In addition, every mission of the US State Department had yet another set of strips for decrypting broadcast messages from Washington. Also this broadcast set was changed from time to time.

From a cryptologic point of view the strip system was a periodic substitution cipher.

Soon after starting the investigations of this encryption procedure we succeeded in identifying the period of 25. We also succeeded to partially decipher some extra long cipher texts. It would have been a hard and tedious work, if not some special circumstances would have occurred. One of these circumstances was the fact that when the United States changed a set of strips at one site it would reuse the same set at another site, instead of cancelling it.

A second fact that was favorable for deciphering was that, because of the U-boat blockade, it was not always possible to replace the strip sets in timely manner at all the field offices. In such cases, e.g. a broadcast message, for a site where the new broadcast strip set had still not arrived, was encrypted with the existing special strip set at that office and which had been in use for a long time.

If now this special procedure was solved - and this was usually the case - the plain text of the broadcast message was known, and there was a clear-cipher text compromise in the new broadcast, from which the strips of the new broadcast procedure were reconstructed.

In this way, a total of 22 different lines and all broadcast messages were read from 1942 to September 1944.

From this successful decipherment must be concluded:

1. It is prohibited to use a key already used in other places.

2. It is not permitted to employ encryption procedures that are vulnerable to clear text-cipher text compromises.

Use of the M-138-A cipher system by the US State Department in WWII

During WWII the US State Department used several cryptosystems in order to protect its radio communications from the Axis powers. The main systems used were the unenciphered Gray and Brown codebooks along with the enciphered codes A1, B1, C1, D1 and the new M-138 strip cipher. 

In the period 1940-1944 German, Japanese and Finnish codebreakers could solve State Department messages (both low and high level) from embassies around the world. The M-138-A strip cipher was the State Department’s high level system and it was used extensively during that period. Although we still don’t know the full story the information available points to a serious compromise both of the circular traffic (Washington to all embassies) and special traffic (Washington to specific embassy). In this area there was cooperation between Germany, Japan and Finland. The German success was made possible thanks to alphabet strips and key lists they received from the Japanese in 1941 and these were passed on by the Germans to their Finnish allies in 1942. The Finnish codebreakers solved several diplomatic links in that year and in 1943 started sharing their findings with the Japanese. German and Finnish codebreakers cooperated in the solution of the strips during the war, with visits of personnel to each country. The Axis codebreakers took advantage of mistakes in the use of the strip cipher by the State Department’s cipher unit.

After further (costly) research new information has come to light. Originally I thought that each US embassy had two sets of strips, the ‘specials’ for direct communications with Washington and the ‘circulars’ for messages sent to several embassies and for intercommunication between embassies.

Recently I also realized that there were additional sets of strips for enciphering the traffic of other US agencies such as the Office of Strategic Services, Office of War Information, Military Intelligence Service, Foreign Economic Administration, War Shipping Administration, Office of Lend-Lease Administration and War Refugee Board.

However there’s more to this story:

1). The circular strips were the 0 dash series. 0-1 was used from 1940 till August 1942. 0-2 from August 1942 till March 1943. From March 1943 a new set was used for each month, 0-3 for March 1943, 0-5 for May, 0-9 for September etc. The circular strips used in 1944 were numbered 0-13 to 0-24 for January-December 1944.

However there were two problems with this system.

One was that the embassy in Bern, Switzerland did not have access to the new strips so it seems that they continued to use the 0-2 strips for some time.

Another problem was that distributing the new circular strips to embassies around the world was not always possible, so some posts were told to continue using the old strips till the new ones arrived. This was clearly a security problem and Erich Huettenhain, chief cryptanalyst of OKW/Chi, said in his manuscript ‘Einzeldarstellungen aus dem Gebiet der Kryptologie’ that they relied on reencodements in their efforts to solve the strip system

‘Ein zweiter für die Entzifferung günstiger Umstand war, daß es wegen der U-Boot-Blockade nicht immer gelang, den auszuwechselnden Stabsatz rechtzeitig an alle Außenstellen zu bringen.  In solchen Fällen wurde z.B. ein cq-Spruch an die Stelle, bei der der neue cq-Stabsatz noch nicht eingetroffen war, mit dem bei der Stelle vorhandenen und seit längerer Zeit in Benutzung befindlichen Spezial-Stabsatz verschlüsselt. Wenn nun dieses Spezial-Verfahren gelöst war, - und das war in der Regel der Fall — so war der Klartext des cq-Spruches bekannt, und es lag ein Klar-Geheim-Kompromiß im neuen cq-Verfahren vor, aus dem die Stäbe des neuen cq-Verfahrens rekonstruiert wurden.’

2). A set of strips titled 00-1 (and key table C) were introduced in late 1943 for enciphering the confidential traffic of other US government agencies. In January 1944 the set 00-2 and 00-3 were sent to the embassies in Algiers (Free French), Turkey, Egypt, UK, Calcutta, Portugal, Spain, India, Sweden, Iran, Iraq, Beirut.

The 00-4 strips replaced set 00-3 in October 1944.

3). In April 1944 the strip system FRIBP was sent to Lisbon, Madrid, Tangier, Algiers, London, Dakar for Cross messages (US-British supply program).

In November 1944 a circular telegram said that the 000-1 strips were used for CROSS and Joint Economic missions messages.

4). In June 1944 Sweden, Spain, Portugal, Egypt, Turkey, Algiers (Free French) received strips to be used for the communications of the WRB - War Refugee Board.

5). In June/July 1943 the strip set 60-3 was introduced for intercommunication between the embassies in Bern, London, Lisbon, Algiers and Washington. From January 1st 1944 the strips 60-5 were used for this purpose.

Madrid also received the strips 60-5 in June 1944.

In July ’44 the 60-5 strips were sent to the US diplomatic facilities in Caserta (for Robert Daniel Murphy) and Rome (for Alexander Comstock Kirk).

6). The embassy in Bern, Switzerland received 6 new code systems in June 1943. In August they received systems 45 and six sixty, with key tables.

In late September 1944 Bern finally received the current circular strips 0-21 to 0-24 and thus use of the 60-5 strips was discontinued.

In early October ’44 Bern stopped using the 00-3 strips for sending messages of other US agencies.

7). During the war the State Department received information pointing to the compromise of the strip cipher system from the embassies in Casablanca, Vichy France, Helsinki, Stockholm and Bern.

8). The embassies in Panama, Turkey, India, Spain reported problems with the strip system. Similar problems (warping of the panel, defects in the paper strips) are mentioned in the military report SRH-366 ‘History of Army Strip Cipher devices’.

9). In August 1943  a strip system was forwarded to Harold J. Tittmann (US Charge d'Affaires to the Vatican).

10). In September ’44 a set of strips were sent to the Special mission of Taylor.

11). In November 1944 the ICSSY cryptographic material was sent to several embassies.

12). Several alphabet strips that are mentioned in decoded Japanese messages were used by embassies around the world. For example:

Strips 22-1 were used in Egypt and Baghdad in 1941, by Vladivostok in 1942-44, by Algiers in 1943.

Strips 38-1 were used by the embassies in Moscow, Ankara, China, Portugal, Australia in 1942-43.

Overall this is very interesting information and sheds some light into the use of the M-138-A strip cipher by the State Department. 

Sources: NARA - RG 59 - Purport Lists for the Department of State Decimal File 1910-1944 – microfilms 444 and 611 – 119.25/Strip Cipher

Update on Case Wicher

The following paragraph has been added in Case ‘Wicher’ – Information from the war diary of Inspectorate 7/VI.

The war diary of Inspectorate 7/VI, in the report of February 1942, says that an investigation of captured Polish files revealed deciphered German radio messages and this material was forwarded to Inspectorate 7/VI to clarify if the compromise was a result of treason or deciphering and if it was the latter to identify the compromised cipher system.

Information on the German Lorenz SZ42 cipher teleprinter

Frode Weierud has created a webpage with links to original German documents on the Lorenz SZ42 cipher teleprinter, used by the German military in WWII.

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. 

Crypto World articles on the ciphers of Czechoslovakia’s government in exile

Information on Czechoslovak ciphers of WWII is available from a series of articles written for crypto world. Jozef Krajcovic has added links to these articles at katkryptolog.

These were hand systems using mostly letter to figure substitution and transposition.