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The Third Reich is Listening
Sep. 30th, 2020 07:40 pmBook Review: The Third Reich is Listening - Inside German Codebreaking 1939-45, by Christian Jennings
I saw this last summer in the gift shop at Bletchley Park, and it later became a Christmas present. The story of how the Plucky Brits broke the Enigma while Jerry arrogantly insisted it was impossible is relatively well known. (Less well known, perhaps, is that the initial work was done by the Poles).
But what was going on the other way around? I'd always thought British messages had been encrypted using one-time pads, essentially unbreakable unless you can acquire said pad. Apparently some messages were encrypted that way, but many were encrypted using other more vulnerable systems, generally substitution tables. The various German agencies were listening to the airwaves just as much, and able to break quite a bit of it. However, organisational and cultural differences from the Allies played a big part: the German codebreaking agencies were fragmented and there was general antipathy and suspicion between those deriving from the military and those deriving from the Nazi party. This would often lead to funding and resourcing difficulties, and also to disbelief at much of the intelligence gathered.
The Germans were able to read traffic from many European nations, both adversaries and neutrals, and the USA, including scrambled transatlantic phone conversations. Amazingly, German codebreakers were able to crack messages encrypted by the Swiss Enigma machine (which was a simpler variant than that used by the German forces), but that still did nothing to raise any alarm. The Kriegsmarine had concerns from time to time that the Enigma was vulnerable and introduced an additional rota used in "Shark" encoding, but always found other explanations for Allied actions that combined with their confirmation bias on the impregnability of the Enigma. There was an assumption that Allied messages would allude to Enigma messages if the machine was compromised, but in fact the Allies were very careful to provide plausible evidence, such as reconnaissance flights, for any Ultra intelligence. The Allies, conversely, were aware that at least some of their communications were compromised, because they discovered them copied into Enigma messages. However, with most of the Allied systems using tabulated data rather than machines, it was a logistical nightmare to change or reissue books, having particularly devastating effect during the Battle of the Atlantic.
This isn't a technical book, and it's quite readable if perhaps a bit dry in places. Certainly it has an important role in rebalancing the landscape of interception and codebreaking in the period.
I saw this last summer in the gift shop at Bletchley Park, and it later became a Christmas present. The story of how the Plucky Brits broke the Enigma while Jerry arrogantly insisted it was impossible is relatively well known. (Less well known, perhaps, is that the initial work was done by the Poles).
But what was going on the other way around? I'd always thought British messages had been encrypted using one-time pads, essentially unbreakable unless you can acquire said pad. Apparently some messages were encrypted that way, but many were encrypted using other more vulnerable systems, generally substitution tables. The various German agencies were listening to the airwaves just as much, and able to break quite a bit of it. However, organisational and cultural differences from the Allies played a big part: the German codebreaking agencies were fragmented and there was general antipathy and suspicion between those deriving from the military and those deriving from the Nazi party. This would often lead to funding and resourcing difficulties, and also to disbelief at much of the intelligence gathered.
The Germans were able to read traffic from many European nations, both adversaries and neutrals, and the USA, including scrambled transatlantic phone conversations. Amazingly, German codebreakers were able to crack messages encrypted by the Swiss Enigma machine (which was a simpler variant than that used by the German forces), but that still did nothing to raise any alarm. The Kriegsmarine had concerns from time to time that the Enigma was vulnerable and introduced an additional rota used in "Shark" encoding, but always found other explanations for Allied actions that combined with their confirmation bias on the impregnability of the Enigma. There was an assumption that Allied messages would allude to Enigma messages if the machine was compromised, but in fact the Allies were very careful to provide plausible evidence, such as reconnaissance flights, for any Ultra intelligence. The Allies, conversely, were aware that at least some of their communications were compromised, because they discovered them copied into Enigma messages. However, with most of the Allied systems using tabulated data rather than machines, it was a logistical nightmare to change or reissue books, having particularly devastating effect during the Battle of the Atlantic.
This isn't a technical book, and it's quite readable if perhaps a bit dry in places. Certainly it has an important role in rebalancing the landscape of interception and codebreaking in the period.