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From: prz@sage.cgd.ucar.edu (Philip Zimmermann)

Subject: Re: IBM-PC random generator, source included
Message-ID: <1992Jun26.080402.27283@ncar.ucar.edu>
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Organization: Climate and Global Dynamics Division/NCAR, Boulder, CO
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Date: Fri, 26 Jun 1992 08:04:02 GMT
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Suppose we assume that Nico's generator produced 1 bit of "true" randomness
for every, say, 3 bits of actual output.  In other words, the output is 
impure randomness, with 1/3 of true randomness buried somewhere in the
output stream, with the other two thirds of output bits being predictible
by some highly sophisticated modeling of the physical system.  (my ratio
of 3-to-1 is just an arbitrary assumption for this example).

Okay, so let's collect 384 bits of Nico's output and reduce it to 128 bits
by running it through MD5.  We have thus captured the true randomness 
that is holographically smeared through his output and distilled it down
with MD5 to the essential undiluted randomness.  We aren't just using
MD5 to mix it up-- we are using it to distill it down.