ANN: obfuscate

[Christian Heimes]

Gregory Ewing wrote:
> Actually I gather it had a lot to do with the fact that
> the Germans made some blunders in the way they used the
> Enigma that seriously compromised its security. There
> was reportedly a branch of the German forces that used
> their Enigmas differently, avoiding those mistakes, and
> the British never managed to crack any of their messages.

IIRC some versions of the Enigma weren't cracked because they used a
different setup and different daily keys.

The predecessor of the Enigma was cracked by Polish scientists years
before WW2 started. Some flaws in the instructions and a known plain
text attack made the crack of the Enigma practical. It took the British
scientists merely hours rather than days or weeks to decipher the daily
key with some smart tricks. For example they started fake attacks on
ships or cities just to have the names in some encrypted reports.