ANN: obfuscate

[Mark Lawrence]

Christian Heimes wrote:
> 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.

I believe that all of Enigma was eventually cracked cos of two major flaws.
1) A letter could never be sent as itself.
2) The Luftwaffe were very poor when compared to the Wehrmacht or 
Kriegsmarine about security so they were a major leak of data regarding 
the other organisations.
3) The users instead of using random three letter combinations kept 
using the same ones.  HIT LER and BER LIN were popular, but the most 
famous one at Bletchley Park was the name of the guy's girlfriend.

Further, the far more powerful Geheimscreiber was also cracked at 
Bletchley by using Colossus.  Sorry some years since I read the book 
about this so can't remember the title or author.

Regards.

Mark Lawrence.