Luftwaffe Personnel spying for Allies?

[Nick Beale]

Originally Posted by RT

further concerning Ultra, was the code "cracked", or "sold", or "found"/ case of the submarine/???

remi

The answer is not simple! Two very good books on this are "Seizing the Enigma" by David Kahn and "Enigma: the battle for the code" by Hugh Sebag-Montefiore.

The Allies broke into the day's Enigma settings by a variety of methods (including statistical analysis and computers) but even when you have done that, the message may still be in another code. The German Navy used a system of two-letter combinations ("bigrams") to denote weather, wind speed/direction etc. A lot of effort went into capturing the relevant code books.