From: "Jörn Engel" <joern@logfs.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>, lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] random: mix all saved registers into entropy pool
Date: Mon, 19 May 2014 19:18:48 -0400 [thread overview]
Message-ID: <20140519231848.GD14563@logfs.org> (raw)
In-Reply-To: <537A8E22.4030400@zytor.com>
On Mon, 19 May 2014 16:05:06 -0700, H. Peter Anvin wrote:
> On 05/19/2014 03:39 PM, Jörn Engel wrote:
> >
> > I would feel fairly confident giving this .25 bits of entropy per
> > event. With 40% unique hashes and assuming at most 1 bit of entropy
> > for a unique hash, that is a fairly conservative underestimate.
>
> Sure, but that is for a specific workload.
The workload is called boot. That is one of the two critical ones -
the other being a cloned VM. If we can gather enough entropy during
boot and somehow avoid the cloned VM problem, we have won. No more
need to feed in entropy from the previous run, which on many embedded
systems won't happen anyway.
If you complained about the limited selection of hardware I tested on,
you would be right. So far it has been x86 kvm and an x86 notebook.
It would be great to get numbers for some embedded system with arm or
mips as well.
Jörn
--
When in doubt, punt. When somebody actually complains, go back and fix it...
The 90% solution is a good thing.
-- Rob Landley
next prev parent reply other threads:[~2014-05-19 23:20 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-19 21:17 [PATCH] random: mix all saved registers into entropy pool Jörn Engel
2014-05-19 21:23 ` Jörn Engel
2014-05-19 22:18 ` H. Peter Anvin
2014-05-19 22:39 ` Jörn Engel
2014-05-19 23:05 ` H. Peter Anvin
2014-05-19 23:18 ` Jörn Engel [this message]
2014-05-20 12:12 ` Andi Kleen
2014-05-20 20:08 ` Jörn Engel
2014-05-21 19:39 ` Andi Kleen
2014-05-21 20:29 ` Jörn Engel
2014-05-21 20:38 ` Jörn Engel
2014-06-04 23:17 ` Jörn Engel
2014-06-10 16:14 ` Theodore Ts'o
2014-06-11 0:10 ` Jörn Engel
2014-06-11 15:27 ` Theodore Ts'o
2014-06-12 20:25 ` Jörn Engel
2014-06-12 20:05 ` Jörn Engel
-- strict thread matches above, loose matches on Subject: below --
2014-02-02 20:36 [PATCH,RFC] random: collect cpu randomness Jörn Engel
2014-02-03 15:50 ` Jörn Engel
2014-02-03 16:37 ` Theodore Ts'o
2014-02-03 18:48 ` Jörn Engel
2014-03-23 18:00 ` [PATCH] random: mix all saved registers into entropy pool Jörn Engel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20140519231848.GD14563@logfs.org \
--to=joern@logfs.org \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.