How did axis code cracking efforts work? The regular episodes focus a lot on Ultra and the US code cracking efforts, but I am curious how much information the axis had on troop movement of the allies? I seem to remember in Anthony Beevor's book on

… [REDACTED*] that the Wehrmacht knew about American troop movements because some of the units did not make an effort to enforce signal intelligence protocols. So I was curious to know what the major axis powers did to crack axis code and what encryption methods the allies had.
*Ardennes 1944

Please only post one (1) question in a topic post - you can post multiple questions, just please keep them separate.


This question is the tip of a potentially interesting iceberg – very interesting – because it opens the door to discussing conflict from all points of view; by no means does this imply looking at the morality or right/wrong of conflicts. We don’t have to dig too deep to learn all about Ultra and Bletchley Park and it’s important that we do. However the corresponding story, that of B-Dienst in this example, is harder to come by and takes a bit of digging. Understandably, German sources for example, are harder to come by whether in German or English, however the questions of how events looked from various points of view is very much worth asking. Again, the issue is not about right or wrong and the big questions overall, it’s more the nitty-gritty, the details that lend themselves to examinations of this type.


Case in point, Indy’s great episode

D-Day - The Biggest Trick in History - WW2 Special

would be even more interesting and informative if we could see the enemy’s reactions to the deceptions.

timeGHOST Army indeed


Ah yes its operation fortitude, it’s in the context of a bigger operation named Operation Body Guard that was directed by Juan Pujol Garcia, a spanish spy working for Nazis but Helping the allies, this topic is very interesting, operation Fortitude is a Masterpiece , the hollywood actors, fake tanks, fake patrols, fake lunches/dinners …


I did a bit of reading; the Germans were indeed very busy and successful at codebreaking, but not to the extent the Allies were. The Enigma machines were ubiquitous. If you can break them - even not even most of them - you get an overview of everything that’s going on, which allows you to build a strategic picture.

The Germans, in contrast, used typical (mathematical) analysis of the various codes the Allies used, of which there were dozens - some for USAAF communicating with itself, some for USAAF communicating with the USN, the USN with itself, the Yugoslavians, the British, US Army within itself, and on and on.

The Germans could and did break these pretty quickly, but the messages they got were almost entirely tactical in nature. (Also, these codes changed regularly, requiring re-analysis.).

For an overview of these code (with examples), I refer you to “Codebreakers: The Comprehensive History of Secret Communications” by David Kahn (“Khan on Codes” Kahn.). It’s a slow read, but its pretty darned complete.