From: "James A. Tunnicliffe" <Tunny@inference.com>
Date: Sat, 5 Oct 1996 13:14:12 +0800
To: "'cypherpunks@toad.com>
Subject: RE: DESCrack keyspace partitioning
Message-ID: <c=US%a=_%p=Inference%l=LANDRU-961004232217Z-1792@landru.novato.inference2.com>
MIME-Version: 1.0
Content-Type: text/plain


>geeman@best.com[SMTP:geeman@best.com] writes:
>Another thinking step: most real-world DES keys are derived from hashes.
>Not (P)RNGs.
>The distributions are **not** uniform.
Oh??
>I am talking about FAMILIES of predictable bit patterns in keys, not any
>specific pattern.
>I'm doing the stats.
[...snip...]

If you've discovered significant biases in MD5, or some other
crypto-strength hash, that could be exploited to speed a keyspace
search, that would be newsworthy indeed.  I'm skeptical, but please
share your results with us.  

[For context, Mike McNally wrote, in part]
>[...] a good
>32-bit CSPRNG has only a 1/2^32 chance of producing any particular
>bit pattern.  Of course, another way of saying that is that it's just
>as likely to get an "obvious" bit pattern as it is to get any other
>one.  You can't just throw away part of the keyspace based on such
>bogus reasoning.  (There may be other reasons to throw away part of
>the keyspace, of course.)

Tunny
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