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Date: Tue, 25 Sep 2012 12:22:41 +0200
From: Pawel Jakub Dawidek <pjd@FreeBSD.org>
To: Dag-Erling =?iso-8859-1?Q?Sm=F8rgrav?= <des@des.no>
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Cc: Jonathan Anderson <jonathan.anderson@cl.cam.ac.uk>,
	John Baldwin <jhb@freebsd.org>, Ben Laurie <benl@freebsd.org>,
	freebsd-security@freebsd.org, RW <rwmaillists@googlemail.com>,
	Mariusz Gromada <mariusz.gromada@gmail.com>
Subject: Re: Collecting entropy from device_attach() times.
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On Tue, Sep 25, 2012 at 11:28:13AM +0200, Dag-Erling Sm=F8rgrav wrote:
> Ben Laurie <benl@freebsd.org> writes:
> > Not that I dislike Pawel's approach, it seems promising, I'm just
> > pointing out the weakness of the analysis.
>=20
> It is also based on fake data.
>=20
> If you give me a couple of days, I'll try to come up with a patch that
> collects and stores attach times during boot so we can gather and
> analyse real data.

Note that this fake data is the hardest to gather entropy from, as it
doesn't interact with any external hardware. I'm all for testing it on
real hardware and I expect to be able to gather even more entropy from
it (so discarding less than top 7 bits). The problem with making
observations during boot takes much, much longer, so it will limit the
number os samples significantly, and as you know the more samples the
better.

--=20
Pawel Jakub Dawidek                       http://www.wheelsystems.com
FreeBSD committer                         http://www.FreeBSD.org
Am I Evil? Yes, I Am!                     http://tupytaj.pl

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