Finding encrytion algorithm

[Mike Rosing]

On Sat, 13 Jul 2002, gfgs pedo wrote:

> can u pls explain how they have statistical
> signatures,pls-
>
>
>  may be using SPN's, i have tried ANSI X9.17 key
> generation with GOST-it did have a negligably small
> skew-it makes me wonder what statistical signature
> they have.The negligable skew is a weakness but not
> high enough to compramise the security of the key used
> from the ANSI x9.17 key gen method.
> pls explain.
> thank u veru much.
>

You're on the right track.  Take several encryption algorithms
of your choice, then use a fixed IV, and the same sets of keys,
and encrypt blocks of 0's.  For each algorithm, compute several sets of
staticstics (a la NIST or DIEHARD).  With 100 blocks of 10 Megabytes
(100 different keys) you should see some interesting differences.

Remember, your question originally was "how can you tell which algorithm",
not "how do you find the key".  Let us know what you find out :-)

Patience, persistence, truth,
Dr. mike