17 Dec
2003
17 Dec
'03
11:17 p.m.
Matt Blaze writes:
Yesterday I mentioned that I'd noticed that "S-1" has a non-uniform distribution of F (Sbox?) outputs - some values appear far more often than others. This means that some values are more likely to be XORed against the cleartext than others. Needless to say, this is a very unusual (and presumably very bad) property - in DES, for example, the Sbox outputs are completely flat.
If it is Skipjack, that would sure explain why they didn't want to release the source code, eh? Maybe there was more than one "back door". -- Jeff