German Code Breakers

Just been watching an old BBC series - Secret War with William Woolard. In the episode about the Battle of the Atlantic they mentioned that the Germans had broken the Allied codes for the convoys and so could locate them and sink them. A lot has been said about Bletchley Park (stayed there several times when it was a BT training school) but I have seen next to nothing about German Code Breakers.

Who where they? where were they located? how did they do it? (not with Colossus I would guess) How successful were they? Who was their Turin? Did they break Russian Codes too?

Hong Kong


A very good book overall outlining the efforts of the Reich to equalise the battle of codebreaking and intelligence.

In short, they were successful in the beginning of the war, intercepting many codes, but after 1942 they lost the battle for intelligence.


Finns had some success in code breaking - mainly Russian codes though. Though it happened separately from the Germans and the Germans did not receive all the Finns had broken - intelligence sharing between the Finns and the Germans (or even the Finns and the Japanese) happened essentially on “you give some, you get some” basis. Bit of text on the topic: (good site with sources, pdf scans and the like related to the topic). I think the most hilarious part of it is the section where the US diplomatic STRIP cipher is being mentioned, the Finns not only broke it but also deconstructed it to the level that the Finns started using it themselves.

Given how the Finns were able to break these top secret diplomatic codes should give some idea why the Finns were so unwilling to directly commit to anything when discussing peace facilitation overtures from the US in 1942-44. If the Finns themselves could do so they likely assumed the Germans could do so as well, and burning the bridges with the Germans while still being in war with the Soviets was not a workable idea.