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Military and intelligence history mostly dealing with World War II.

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  • 05/13/18--23:33: Another correction
  • After the release of TICOM report D-83, in The British Typex cipher machine I’ve changed the paragraph

    In the period 1940-41 the cipher research department of the German Army’s signal intelligence agency Inspectorate 7/VI had several talented mathematicians (Pietsch, Steinberg, Marquart, SchulzRinow) tasked with examining difficult foreign cryptosystems. The war diary of Inspectorate 7/VI shows that these individuals investigated the Typex device and by May ’41 had ascertained that it was mainly used by the RAF and was issued with 10 rotors. Their research on its internal cipher operation however was slow and had not led to any breakthrough. Things changed in May when they visited the facilities of the Signal Intelligence Agency of the Supreme Command of the Armed Forces - OKW/Chi and were able to examine a Typex machine captured at Dunkirk. The device worked according to the Enigma principle with the two rotors on the left remaining stationary and the wiring of the entry and reflector wheels could be recovered’  

    into


    In the period 1940-41 the cipher research department of the German Army’s signal intelligence agency Inspectorate 7/VI had several talented mathematicians (Pietsch, Steinberg, Marquart, SchulzRinow) tasked with examining difficult foreign cryptosystems. The war diary of Inspectorate 7/VI shows that these individuals investigated the Typex device and by May ’41 had ascertained that it was an Enigma type device with 5 multistep rotors, the last two of which did not move during encipherment. Their research was confirmed in May, when they visited the facilities  of the Signal Intelligence Agency of the Supreme Command of the Armed Forces - OKW/Chi and were able to examine a Typex machine captured at Dunkirk. The device worked according to the Enigma principle with the two rotors on the left remaining stationary and the wiring of the entry and reflector wheels could be recovered’. 

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  • 05/25/18--07:09: TICOM DF-196
  • The NSA FOIA/MDR office has declassified the TICOM report DF-196 ‘Report on Russian decryption in the former German Army’.



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  • 05/30/18--23:11: TICOM report DF-217
  • I’ve uploaded TICOM report DF-217 ‘Russian cipher device K-37’, written by dr Grimmsen. 


    Also added a summary and pics in The Soviet K-37 ‘Crystal’ cipher machine.

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  • 06/01/18--09:19: Update
  • In The Japanese FUJI diplomatic cipher 1941-43 I’ve added the following information under the paragraph ‘Pers Z effort’:

    More information is available from the TICOM report DF-31B ‘How J.B. 57 Japanese Letter System Was Solved’, written by the cryptanalysts Annalise Huenke and Hans Rohrbach


    The first break into system JB 57 came through two messages that had the same indicator (meaning they used the same transposition key). Once these were solved the system was identified as a transposed code, using a stencil.



    Solution of this indicator led to the decipherment of more messages and dr Kunze (head of the ‘Mathematical Cryptanalytic Subsection’ of Pers Z) was able to use the information recovered in order to solve more message indicators. The inroads made by the solution of indicator groups led to the eventual recovery of the underlying code by the linguistic group and the current exploitation of this traffic.



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    Boris Kavalerchik, tank expert and author of the Journal of Slavic Military Studies article ‘Once Again About the T-34’ has published a book on ‘The Tanks of Operation Barbarossa’.


    Summary:


    When the Germans invaded the Soviet Union in 1941 the Red Army had four times as many tanks as the Wehrmacht and their tanks were seemingly superior, yet the Wehrmacht won the border battles with extraordinary ease the Red Armys tank force was pushed aside and for the most part annihilated. How was this victory achieved, and were the Soviet tanks really as well designed as is often believed? These are the basic questions Boris Kavalerchik answers in this absorbing study of the tanks and the tank tactics of the two armies that confronted each other at the start of the war on the Eastern Front. Drawing on technical and operational documents from Russian archives, many of which were classified until recently and are unknown to Western readers, he compares the strengths and weakness of the tanks and the different ways in which they were used by the opposing armies. His work will be essential reading for military historians who are interested in the development of armoured warfare and in this aspect of the struggle on the Eastern Front.

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  • 06/11/18--22:55: Update
  • I’ve added a Q&A section in The Tanks of Operation Barbarossa.

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    During WWII the US State Department used several cryptosystems in order to protect its radio communications from the Axis powers. For low level messages the unenciphered Gray and Brown codebooks were used.  For important messages four different codebooks (A1, B1, C1, D1) enciphered with substitution tables were available.


    Their most modern and (in theory) secure system was the M-138-A strip cipher. Unfortunately for the Americans this system was compromised and diplomatic messages were read by the Germans, Finns, Japanese, Italians and Hungarians. The strip cipher carried the most important diplomatic traffic of the United States (at least until mid/late 1944) and by reading these messages the Axis powers gained insights into global US policy.


    Germans, Finns and Japanese cooperated on the solution of the strip cipher. In 1941 the Japanese gave to the Germans alphabet strips and numerical keys that they had copied from a US consulate in 1939 and these were passed on by the Germans to their Finnish allies in 1942. Then in 1943 the Finns started sharing their results with Japan. 


    Finnish solution of State Department cryptosystems


    During WWII the Finnish signal intelligence service worked mostly on Soviet military and NKVD cryptosystems however they did have a small diplomatic section located in Mikkeli. This department had about 38 analysts, with the majority working on US codes.

    Head of the department was Mary Grashorn. Other important people were Pentti Aalto (effective head of the US section) and the experts on the M-138 strip cipher Karl Erik Henriksson and Kalevi Loimaranta.


    Their main wartime success was the solution of the State Department’s M-138-A cipher. The solution of this high level system gave them access to important diplomatic messages from US embassies in Europe and around the world. 



    Operation Stella Polaris


    In September 1944 Finland signed an armistice with the Soviet Union. The people in charge of the Finnish signal intelligence service anticipated this move and fearing a Soviet takeover of the country had taken measures to relocate the radio service to Sweden. This operation was called Stella Polaris (Polar Star).


    In late September roughly 700 people, comprising members of the intelligence services and their families were transported by ship to Sweden. The Finns had come to an agreement with the Swedish intelligence service that their people would be allowed to stay and in return the Swedes would get the Finnish crypto archives and their radio equipment. At the same time colonel Hallamaa, head of the signals intelligence service, gathered funds for the Stella Polaris group by selling the solved codes in the Finnish archives to the Americans, British and Japanese. 


    The Stella Polaris operation was dependent on secrecy. However the open market for Soviet codes made the Swedish government uneasy. In the end most of the Finnish personnel chose to return to Finland, since the feared Soviet takeover did not materialize. 


    The Higgs memorandum


    In September 1944 colonel Hallamaa met with L. Randolph Higgs, an official of the US embassy in Sweden and told him about their successes with US diplomatic codes and ciphers.


    This information was summarized in a report prepared by Higgs, dated 30 September 1944.


    The report can be found in the US National Archives - collection RG 84 ‘Records of the Foreign Service Posts of the Department of State’ - ‘US Legation/Embassy Stockholm, Sweden’ - ‘Top Secret General Records File: 1944’.








    Higgs met with colonel Hallamaa on September 29 and the OSS officials Tikander and Cole were also present during their discussion.


    Hallamaa stated that he was an administrator, not a cryptanalyst and about 10-12 of his men worked on US diplomatic codes.


    His unit had solved the US codes Gray, Brown, M-138-A strip cipher and enciphered codebooks (probably the A1, B1, C1).


    The high level M-138-A system had been solved mostly by taking advantage of operator mistakes such as sending strip cipher information on other systems that had already been broken or sending the same message in different strips one of which had been broken.


    The strip cipher was considered a strong encryption system and had been adopted by the Finns for some of their traffic.


    Important diplomatic messages from the US embassies in Switzerland, Sweden and Finland were read by the Finnish codebreakers.


    Regarding Bern, Switzerland most of the messages dealt with intelligence matters:

    Replying to my request for information regarding the contents of the messages from our Legation in Bern to the Department, Col. Hallamaa said the great bulk of them were intelligence messages dealing with conditions in Germany, France, Italy and the Balkans. He spoke in complimentary terms about ‘Harrison’s’ information service’.


    Regarding Helsinki, Finland Hallamaa stated that thanks to the decoded diplomatic traffic they were always informed of current US policy initiatives:


    Col. Hallamaa said that they always knew before McClintock arrived at the Foreign Office what he was coming to talk about’.


    Hallamaa revealed a lot of confidential information to the Americans and volunteered to have some of his experts interviewed. 

    The interview was conducted on friendly terms with Higgs stating; ‘Col. Hallamaa was most pleasant and seemed to be entirely frank and open regarding the matters discussed’.


    Additional information: In November 1944 the US cryptanalysts Paavo Carlson of the Army’s Signal Security Agency and Paul E. Goldsberry of the State Department’s cipher unit interviewed Finnish officials regarding their work on US codes. Their report can be found here.

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  • 07/06/18--06:39: Update
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  • 07/17/18--05:31: ‘Experiences 1920-1939’
  • Site governmentattic.com has uploaded the NSA report ‘Experiences 1920-1939’ by Brigadier John H. Tiltman.

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  • 07/29/18--03:26: TICOM DF-174A

  • The report has information on the Enigma cipher machine, the SG 39 cipher machine and the Enigma modification Lückenfüllerwalze.

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  • 08/18/18--06:12: Update
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  • 09/08/18--22:57: Remaining research projects
  • What files am I still trying to locate? Let’s see.


    1). TICOM report I-40

    I requested this file from the NSA FOIA office in 2015. It was quickly located and placed in the review queue. However it has not been declassified yet…

    2).  NAAS 5 reports:

    There are two German Army signal intelligence reports covering the work of the NAAS 5 unit for the second half of 1944:

    E-Bericht 4/44 der NAAst 5 (Berichtszeit 1.7-30.9.44) dated 10.10.44 

    E-Bericht der NAAst 5 (Berichtszeit 1.10.44-30.12.44) dated 14.1.45

    According to the NSA FOIA office they are probably in transfer group TR-0457-2017-0010. 

    These files have been sent to the US National archives so I have to wait for NARA to process these files and then I can ask them to locate the NAAS 5 reports (assuming they are really there…).

    3). Henriksson report:

    According to my information on 18 October 1944 there was a meeting in Sweden between the US officials Wilho Tikander and L. Randolph Higgs and the Finnish officials Reino Hallamaa and Karl-Erik Henriksson.

    Henriksson was the Finnish expert on US codes and ciphers and in this meeting he gave the Americans detailed information on the compromise of their diplomatic communications.


    My researcher and the NARA research department have checked the files in collection RG 84 ‘Records of the Foreign Service Posts of the Department of State’ - ‘US Legation/Embassy Stockholm, Sweden’ - ‘Top Secret General Records File: 1944’ but they could not locate this file.

    Thus I have filed FOIA requests with NARA and the State Department regarding this file. Maybe I’ll get lucky.

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    During WWII the US State Department used several codebooks for enciphering radio telegrams. These were the low level Gray and Brown codes and the high level A1, B1 and C1 codes.


    The latter codebooks were used with substitution tables.

    It is clear that the German codebreakers were able to solve the substitution tables used with the A1 and C1 codes till late 1943 because these were given to the Japanese and decoded by the Allies in late 1944 (1):


    According to a message of the Japanese military attaché the C1 code continued to be used by the US embassy in Bern, Switzerland so those messages could be read in 1944 (2):


    Were the Germans also able to read messages enciphered on the A1 codebook in 1944?

    The book ‘Hitler, the Allies, and the Jews’ by Shlomo Aronson mentions a message solved by the codebreakers of OKW/Chi (German High Command’s deciphering department) (3):

    At the same time, the OKW/Chi decrypts tell us in their way what the Allies were doing in various ways, including the hectic activities of WRB's operatives upon its inception. Thus, the following cable from Washington, dated February 9, 1944, from the State Department and signed by Secretary of State Cordell Hull but in fact sent by the WRB to the American Legation in Bern, dealt with funds made available to the International Red Cross (ICRC) in Geneva to help Jews in Rumania, Croatia, Hungary, Slovakia, and Theresienstadt by the Joint Distribution Committee (AJDC), as authorized by the Treasury Department’.


    The original message can be found in the US National Archives (4) and the classification is SECRET.


    The note on the first page says A-1 so I assume that it was sent using the A-1 codebook. 

    Thus it seems that the Germans continued to read diplomatic traffic sent on the A-1 code even in 1944.

    Sources:

    (1). US National Archives - collection RG 457 - Entry 9032 - box 1.018 - NR3225 ‘JAT write up - selections from JMA traffic'

    (2). UK National archives HW 40/132 ‘Decrypts relating to enemy exploitation of US State Department cyphers, with related correspondence’.


    (4). US National Archives - Microfilm Publication M1284, roll 38, indexed to file ‘840.48 Refugees/5195’. 

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  • 09/29/18--02:29: Greek civil war decrypts

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