3 ms·

This is a great read ..... We hear a lot about smart Allied code breakers breaking German and Japanese code - anyone know what the Allies' codes were like? wer

This is a great read ..... We hear a lot about smart Allied code breakers breaking German and Japanese code - anyone know what the Allies' codes were like? were they broken?

willvarfar 7y ago
The biggest thing hindering the Germans was organizational - they had lots of units that competed with each other. A good list of their success https://en.wikipedia.org/wiki/German_code_breaking_in_World_War_II https://en.wikipedia.org/wiki/German_code_breaking_in_World_... The Germans weren't the only ones with internal division sapping effectiveness; on the eve of Pearl Harbor the US managed to crack the Japanese diplomatic cipher. However, two teams, nominally organised and housed together but still vying with one another, tried to own it exclusively. To keep things fair, the navy team and the army team took turns cracking it. There was a lot of heat about who knew what when later. As the Germans approached Moscow, the British Embassy evacuated. Years later, a bug was discovered cemented into the roof of the cipher room, presumed to have been planted while the embassy was evacuated. So clearly, despite the present danger on the outskirts, some people in Moscow were thinking of the future wars... My notes on who broke Enigma when and where https://williame.github.io/post/145745642718.html https://williame.github.io/post/145745642718.html Someone who doesn't get as much attention as Alan Turing and Gordon Welchman is W. T. Tutte. His feat of breaking the Fish cipher is perhaps the greatest mental gymnastics ever? An unsung hero during this period was Arne Beurling in Sweden. I came across the T52 in a museum in Stockholm and was completely surprised. Its a variant of the Fish cipher and the Arne broke it just like Tutte did in England. I'd have to look it up but perhaps Arne was first? Amazing too. https://en.wikipedia.org/wiki/Arne_Beurling https://en.wikipedia.org/wiki/Arne_Beurling I'd love to hear about things I've missed!
- raxxorrax 7y ago
  Neat summary. I wonder how many encrypted texts they actually got to be able to come up with a decryption technique. Cannot imagine it being too many.
jjtheblunt 7y ago
One example is https://en.wikipedia.org/wiki/Code_talker https://en.wikipedia.org/wiki/Code_talker
Isamu 7y ago
SIGSALY was an unbreakable voice scrambler that relied on early digital techniques, pretty interesting: https://spectrum.ieee.org/geek-life/hands-on/rebuilding-a-piece-of-the-first-digital-voice-scrambler https://spectrum.ieee.org/geek-life/hands-on/rebuilding-a-pi... IIRC, it was unbreakable because it amounted to a one-time-pad that was shared between the transmitter and receiver.

This is a great read ..... We hear a lot about smart Allied code breakers breaking German and Japanese code - anyone know what the Allies' codes were like? were they broken?

willvarfar 7y ago

The biggest thing hindering the Germans was organizational - they had lots of units that competed with each other. A good list of their success https://en.wikipedia.org/wiki/German_code_breaking_in_World_War_II https://en.wikipedia.org/wiki/German_code_breaking_in_World_... The Germans weren't the only ones with internal division sapping effectiveness; on the eve of Pearl Harbor the US managed to crack the Japanese diplomatic cipher. However, two teams, nominally organised and housed together but still vying with one another, tried to own it exclusively. To keep things fair, the navy team and the army team took turns cracking it. There was a lot of heat about who knew what when later. As the Germans approached Moscow, the British Embassy evacuated. Years later, a bug was discovered cemented into the roof of the cipher room, presumed to have been planted while the embassy was evacuated. So clearly, despite the present danger on the outskirts, some people in Moscow were thinking of the future wars... My notes on who broke Enigma when and where https://williame.github.io/post/145745642718.html https://williame.github.io/post/145745642718.html Someone who doesn't get as much attention as Alan Turing and Gordon Welchman is W. T. Tutte. His feat of breaking the Fish cipher is perhaps the greatest mental gymnastics ever? An unsung hero during this period was Arne Beurling in Sweden. I came across the T52 in a museum in Stockholm and was completely surprised. Its a variant of the Fish cipher and the Arne broke it just like Tutte did in England. I'd have to look it up but perhaps Arne was first? Amazing too. https://en.wikipedia.org/wiki/Arne_Beurling https://en.wikipedia.org/wiki/Arne_Beurling I'd love to hear about things I've missed!

raxxorrax 7y ago
Neat summary. I wonder how many encrypted texts they actually got to be able to come up with a decryption technique. Cannot imagine it being too many.

jjtheblunt 7y ago

One example is https://en.wikipedia.org/wiki/Code_talker https://en.wikipedia.org/wiki/Code_talker

Isamu 7y ago

SIGSALY was an unbreakable voice scrambler that relied on early digital techniques, pretty interesting: https://spectrum.ieee.org/geek-life/hands-on/rebuilding-a-piece-of-the-first-digital-voice-scrambler https://spectrum.ieee.org/geek-life/hands-on/rebuilding-a-pi... IIRC, it was unbreakable because it amounted to a one-time-pad that was shared between the transmitter and receiver.