Re: advice sought on key/data histogram analysis of rijndael/128 and serpent

lkcl@lkcl.net writes:
> the basic premise of the test i am performing is to pick an initial
> key with only one bit set, to encrypt some input data, to XOR in one
> bit into the output, then to use the output as the KEY for the next
> encrypt, repeat the process N times.

AES is supposed to act like a random permutation if the key is random
and uniformly distributed. If the keys are special and related, you
can get structure in the output (related-key attack). AES does not
claim to still act random when the keys are non-random. I'm not sure
if that applies to what you're doing, which I didn't read very
carefully. However, if you're not using random keys, maybe nothing is
wrong with either AES or your code.
Received on Mon Oct 17 20:48:35 2005