From: JonWienke@aol.com
Date: Sun, 7 Apr 1996 05:35:15 +0800
To: cypherpunks@toad.com
Subject: Re: Spinners and compression functions
Message-ID: <960406122835_370230637@emout09.mail.aol.com>
MIME-Version: 1.0
Content-Type: text/plain


In a message dated 96-04-06 11:26:26 EST, Perry Metzger sez:

>Actually, it doesn't. The entropy present from a reasonable source
>like keyclick timings is much much lower than the output of pkzip is
>going to suggest to you.

I am not saying that the output of the compression function has 8 bits of
entropy per byte, but rather that it will have a more consistent entropy
level per byte than the input to the function.  (Especially in the case of
idle loop timings, where the entropy fluctuates considerably, depending on
what the computer is doing.)  If you want to be conservative, you can assume
the output of the compression function has only 1 bit (or even less, if you
are really paranoid) of entropy per byte, and adjust your seeding
requirements accordingly.

Jonathan Wienke