lkml.org 
[lkml]   [2013]   [Feb]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [RFC][PATCH] Entropy generator with 100 kB/s throughput
From
I'm so sorry, something went terribly wrong with gmail/thunderbird :-(

2013/2/22 Nick Kossifidis <mickflemm@gmail.com>:
> Hello all,
>
> It's nice to see there is still discussion on the matter of using cpu
> timings for entropy. In general using cpu timings for gathering entropy is a
> nice idea but it's not that unpredictable. If someone can profile the system
> he/she can get enough infos to predict (to some point) the generator's
> outcome, especially during boot/reboot. You might pass the tests on a single
> run but if you try to compare the runs e.g. when booting the system multiple
> times you'll see they are correlated.
>
> Take a look at this:
>
> http://dl.dropbox.com/u/11670313/runtime-data.tar.bz2
>
> It's the output of this patch, before passing data to the entropy pool (btw
> did anyone review this patch or should I resend it ?):
>
> https://patchwork.kernel.org/patch/1759821/
>
> If you plot the datasets you'll see e.g. that across reboots you get a very
> similar distribution. It is somehow different across boots but still there
> is some correlation there too, notice the difference when fsck runs, still
> not much.
>
> The distribution is good in general, for mixing it with the rest in the
> system's entropy pool, but on its own I don't think it's enough, especially
> without crypto post-processing.



--
GPG ID: 0xEE878588
As you read this post global entropy rises. Have Fun ;-)
Nick


\
 
 \ /
  Last update: 2013-02-22 13:01    [W:0.112 / U:0.912 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site