Re: [dsfjdssdfsd] what not to do...

Theodore Ts'o <tytso@mit.edu> Wed, 02 April 2014 16:34 UTC

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Date: Wed, 2 Apr 2014 12:33:54 -0400
From: Theodore Ts'o <tytso@mit.edu>
To: Donald Eastlake <d3e3e3@gmail.com>
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Cc: "dsfjdssdfsd@ietf.org" <dsfjdssdfsd@ietf.org>, Sandy Harris <sandyinchina@gmail.com>
Subject: Re: [dsfjdssdfsd] what not to do...
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On Wed, Apr 02, 2014 at 10:57:34AM -0400, Donald Eastlake wrote:
> Hi,
> 
> Yes, the "bad ideas" section of RFC 4086bis
> (draft-eastlake-randomness3-00) seems like a good place to collect
> additional things not to do.
> 
> I am planning to update that draft soon...

Is this list the best list of have discussions about that draft?  Or
are you planning on using some other wg list?

Some things that I might add as caveats is that the recommendations
about using disk timing is based on research done decades ago, and
disk drives have changed quite a bit since then.  I believe there
probably is *some* entropy in spinning disks, but it may not be as
much as possible.

In the section about clocks, it might be worthy to note that on modern
CPU's, very often many clocks are derived from a single master
oscillator.  If there are subsystems where you have two clocks that
are _not_ derived from the same oscillator, there may be an
opportunity to pick up a few bits of entropy.  (And I suspect that's
probably one of the remaining sources of entropy from disk drives
these days.)

Cheers,

						- Ted