More "S-1" foolishness

[Jeff Barber]

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