Germany’s World War Two Codebreakers: BP Talk 18/8/2021

Discussion in 'WW2 Museums. Events, & places to see.' started by davidbfpo, Aug 3, 2021.

  1. davidbfpo

    davidbfpo Patron Patron

    Landed via Twitter:
    The event is free, a donation would be nice. Details: BP Presents: Christian Jennings
  2. davidbfpo

    davidbfpo Patron Patron

    Listening to this fascinating talk and just looked up his bio and what he books he has written:
    From his agent's website: Andrew Lownie Literary Agency :: Authors :: Christian Jennings and details of his books via:
  3. davidbfpo

    davidbfpo Patron Patron

    I am awaiting a decision from Bletchley Park Trust if the recording can be released to this group or whether it will appear on their website.
  4. davidbfpo

    davidbfpo Patron Patron

    Alas the recording cannot be released, nor will it appear on the BP website - conditions given by the speaker. One day I will post a summary.
  5. davidbfpo

    davidbfpo Patron Patron

    This is my summary of the talk, both below and as an attachment.

    ‘The Third Reich is Listening: Inside German codebreaking 1939–45’ by Christian Jennings

    These are my notes of his Bletchley Park Trust talk, not a transcript. In a few places my initial research has been added, yes, it is mainly from Wiki as a starting point. The topic has not been personally visited for many years and I think he reveals new information, some of which is very odd such as the Yalta SIGINT episode.

    Much of his research was in the TICOM Archive, the post-VE-Day UK-US operation to gather signals intelligence (SIGINT) material, such as documents and memoirs; plus, interviews whilst German civilian and military were in detention.[1]

    The Head of German naval SIGINT (B-Dienst[2]), a trained cryptanalyst, Wilhelm Tranow[3], had served in WW1 and provided a mass of information – possibly in a memoir. He disappeared after 1945, it is suspected he was taken to the USA and after his return to West Germany he wrote nothing about his wartime service.

    The Royal Navy pre-1939 did not change codebooks frequently and many of their ships around the world regularly broadcast their position. The RN used five figure codebooks and Tranow identified the tables used protractors, so codes could be broken. Pre-1939 B-Dienst had a 35-40% success rate in breaking RN codes; on the outbreak of war the RN did not start using new codebooks.

    The German SIGINT agencies (there were ten) listened to forty-one nations and sometimes intercepted obscure nations radio traffic, e.g., Bolivia and Ethiopia. This could be useful to codebreaking as it gained access to other nation’s radio traffic and other nations had a clearer possible gain, e.g., Ireland, Portugal, and Sweden.

    After the nationalist victory in the Spanish Civil War in 1938 German SIGINT established stations in Seville, the Canary Islands and Spanish Morocco cities (Ceuta and Melilla?).[4]

    The Italian (naval?) agencies focus was the RN codes and they identified that messages invariably started with ‘To’ and ended with ‘From’, so access was gained. It appears that the RN overlooked this weakness.

    At the height of the Battle of the Atlantic B-Dienst gained 100% access to the UK and US convoy codes, so could state twelve hours before arrival where a convoy would be. In April 1943 B-Dienst SIGINT enabled forty-one U-Boats to an area four hundred miles south of Greenland, guiding the submarines onto two convoys, sinking twenty-two ships. Only then the Allies realise their convoy codes had been broken for three and half years; this was confirmed by pots-war Allied reports.

    (Unclear which German agency was responsible, possibly the Foreign Ministry’s intelligence department) In September 1941 the US military attaché at the Cairo Embassy had his safe burgled and the codebook(s) were removed for a day and then returned. This attaché was new in post and was sent to assess what help could be given to the 8th Army. His reports back to Washington DC were re-transmitted by the US military attaché in Rome. Rommel was able to identify 8th Army positions and more as a result.[5]

    The Luftwaffe SIGINT agency established listening posts across Italy and the Aegean. They successfully intercepted the USAAF bomber raids on Rumanian oilfields and Ploesti refineries, on 1st August 1943, in Operation Tidal Wave[6] and shot down, in two or three raids, fifty-five aircraft (of 177) and six hundred aircrew were lost.

    In Operation Barbarossa German SIGINT for the first eighteen months found the Soviets were using old codebooks and so gained an advantage – this lasted till April 1943, with the end of the Stalingrad siege (and applied generally in other theatres such as the Battle of the Atlantic).

    After April 1943 Germany was on the defensive and retreating the German SIGINT gain was far less important, especially since there were few resources to respond. With ten agencies duplication was always a problem.

    German leadership up to and including Hitler did not like ‘bad news’ being presented to them. Jennings refers to a report on a visit (by Tranow?) to an Italy-based SIGINT unit, which found staff were less proud of their work, results had less impact now and this affected morale.

    In the Sicily campaign the Germans captured a standard US Army Hegelin code machine[7] and / or codebooks; this enabled them to identify Allied objectives and assisted in the unhindered evacuation of several divisions to the Italian mainland.

    The codebooks of the US 82nd and 101st Airborne Divisions were captured on D+1 (not readily confirmed), this enabled some tactical gains, but was not a great gain.

    After the July 1944 bomb plot to kill Hitler (Von Stauffenberg’s briefcase bomb in the East Prussia HQ conference room[8]) all the German agencies were pulled apart, with senior (Army) officers removed form their positions. This greatly reduced the willingness to give Hitler ‘bad news’. With the Red Army advancing, what did it matter to be told which division was attacking you?

    During the Yalta Conference, in early February 1945, the Turks were listening in to the UK-US radio traffic, which was passed to the Hungarians, who sold it the SS in Budapest and then was given (possibly partially) to Army SIGINT for their senior officer to visit Hitler’s HQ. There is a transcript of the meeting in the (TICOM) archives, which a US officer has added ‘He should give up his day job’ or similar remark being made by Hitler, who ignored the intelligence. (This is an unusual episode IMHO).

    Q&A Session

    (Question missed) Hitler’s entourage disliked the SIGINT agencies expertise and experts, a good number of which were civilians or academics and whose number, in service and as possible recruits were reduced by the race laws passed in 1935.[9] Tranow was told by a SS officer he had made a disparaging comment in 1938 and this was on record as him being anti-Nazi. Such prejudices and attitudes affected manpower / resource allocation decisions.

    B-Dienst at its peak had seven hundred staff, with possibly fifty cryptanalysts and the ten agencies had a twelve to fourteen thousand strong establishment. As the German manpower crisis worsened for the Army a request for seven hundred more men was equivalent to a full infantry battalion.

    Bletchley Park used 75% women in its establishment, did the Germans use such numbers? The Luftwaffe used many women, hundreds of them and there is an inspection report that noted women were more reliable, calmer, made less fuss and were better disciplined. Very few rose through the ranks and were know there were only three senior staff. One was Ursula Hagen[10], based in Germany (Berlin?), who at the time of the Schweinfurt bombing (August 1943) was working in very poor conditions.

    Why didn’t the Germans identify that their Enigma codes were being broken? The Germans blamed DF, radar, increasingly air superiority, spies amongst the staff and more. There was an inquiry in 1944 into Enigma security, this did not identify any full message content had been revealed beyond basic information. Operator error mistakes were blamed.

    (Question missed or a continuation) Jennings specifically referred to Convoy ON127 from Liverpool to Newfoundland in September 1942, when HMCS Ottawa, commanded by Captain Hugh Francis Pullen, was sunk. See (so far un-read):

    Post-war examination of B-Dienst documents found that they had not found anything wrong with Enigma.

    Japanese codes were not attacked, the Japanese gave what it was requested to do via their Berlin Ambassador.[11] Note the Ambassador did an inspection visit of the Normandy coastal defences and his report was read by the Allies before it reached Tokyo. (This episode has been written about before in the journal Intelligence and National Security).

    There was some sharing of SIGINT with the Italians till their surrender in 1943, at times there was no exchange. The Italians had very good cryptanalysts and they gave more to the Germans than they got back.

    We know the German rocket scientists moved to the USA after Germany’s defeat. What happened to the German cryptanalysts? A “considerable number went to work for the Allies and some for the USSR”. In my book I have a list of the mainly civilian staff, some of whom remained in detention (not POW) camps in Germany for two and half years. On a rough calculation 25% went home, 25% worked for the USA in Germany and 25% captured by the USSR worked for them.

    What were the lessons of the past for today?

    · Intelligence does not exist in a vacuum

    · You must have resources to respond to SIGINT gains

    · SIGINT is a novelty, old SIGINT cannot be used

    · What is secret in one nation, is open in another

    · Effective handling methods and structures

    · Human error will happen in SIGINT

    The book this talk is based is The Third Reich is Listening: Inside German codebreaking 1939–45 (pub. Paperback in 2019).[12]

    Finally, Jennings has written a book ‘Anatomy of a Massacre: How the SS Got Away with War Crimes in Italy’ (pub. April 2021)[13] and is currently writing a book ‘Syndrome K’ on the Italian resistance to the Holocaust, due out later in 2020 or 2021.[14]

    [1] There are four short ww2talk threads on TICOM

    [2] See: B-Dienst - Wikipedia

    [3] See: Wilhelm Tranow - Wikipedia

    [4] This would make sense and I would expect others have written about this Spanish liaison

    [5] See the first article found: Intercepted Communications, A Secret Ear for the Desert Fox - September '96 World War II Feature and the second: Christos military and intelligence corner: US military attaché codes of WWII

    [6] See: Operation Tidal Wave - Wikipedia This underplays the role of German SIGINT knowledge

    [7] See: M-209 - Wikipedia A tactical level code machine, Wiki does not refer to this capture, but acknowledges Germany successfully broke 10-30% of traffic in 1943.

    [8] See for the plot only: Claus von Stauffenberg - Wikipedia

    [9] See: Nuremberg Laws - Wikipedia

    [10] Mentioned as a staff section head in the German Foreign Office SIGINT agency. See: Pers Z S - Wikipedia

    [11] See: Hiroshi Ōshima - Wikipedia

    [12] See:

    [13] See:

    [14] See, the first account found: Syndrome K: the fake WW2 disease that saved Jews from the Nazis

    Attached Files:

    JohnH, Charley Fortnum and Osborne2 like this.
  6. Osborne2

    Osborne2 Well-Known Member

    Davidbfo, thank you for taking the time to compile this resume. It strikes me that the German leadership had not read Sun Tsu's Art of War -'know your enemy'.

    Your resume of Jennings shows that they had not sufficiently grasped the principle of know your enemy. They had taken early advantage of early doors (RN, USSR, flawed/available codes and US laxity) opportunity, but when the doors closed they had not got the organisations staffed and equipped to break into the more robust replacements. The UK/US largely integrated all their intelligence gathering from POW interrogation/recording, through SIGINT speech/morse/ teleprinter capture across all contributing sources to formulate their strategies. Operation Fortitude was one example of how to use much of this material on a large scale.

    Thank you once again.

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