[Kim_Bruning]

I bet you were told that the code brakers at Bletchley Park only decrypted "Enigma" during WWII. That is actually an old story, and is not entirely correct.

It turns out the Germans also had a much more advanced cypher called Lorenz, which required rather more advanced hardware, including the world's first programmable electronic computer. This was Colossus.

[hackcasual]

The biggest difference between enigma and Lorenz was Lorenz was broken without seeing a physical machine. It was broken as a very long message was transmitted twice with minor changes. That allowed recovery of of the plaintext and key stream