
For Sale: A Tricky Cipher from WWII - vaultcool
https://www.atlasobscura.com/articles/for-sale-a-cipher-from-wwii
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otras
> Since the Nazis reset the codes nearly every day, the teams started from
> scratch each morning. Decoding them was a tall order, because the
> permutations were complex: Each rotor had 26 possible positions, and no
> letter was encoded to itself.

The permutations were very complex, but the fact that no letter was encoded to
itself was actually beneficial to those decrypting the messages. From
Wikipedia [0]:

" _A major weakness of the system, however, was that no letter could be
enciphered to itself. This meant that some possible solutions could quickly be
eliminated because of the same letter appearing in the same place in both the
ciphertext and the putative piece of plaintext._ "

[0]:
[https://en.wikipedia.org/wiki/Cryptanalysis_of_the_Enigma#Th...](https://en.wikipedia.org/wiki/Cryptanalysis_of_the_Enigma#The_Enigma_machines)

