[52927] in Cypherpunks
Re: Random Number Testing
daemon@ATHENA.MIT.EDU (Carl Ellison)
Fri Mar 29 14:24:57 1996
Date: Fri, 29 Mar 1996 13:45:26 -0500
To: "Deranged Mutant" <WlkngOwl@UNiX.asb.com>
From: cme@cybercash.com (Carl Ellison)
Cc: Jeff Barber <jeffb@sware.com>, cypherpunks@toad.com
At 01:34 3/29/96, Deranged Mutant wrote:
>> - Is this apparent entropy really *unpredictable* (the most useful
>> definition of "random" for cryptographic purposes)?
>
>Good question. You'd need to look for patterns. Barring none, you'd
>have to guess the factors that lead to the entropy, and then see if
>there's a way to reverse-engineer it. (Perhaps use a stripped down
>system and build it up, or disable some of the hardware and OS
>features etc.)
There's more to unpredictability than patterns or their absense. In
addition, you have to look at the ability of anyone else on the same
machine to learn things about the data you're gathering and subtract the
entropy of that commonly available data.
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