Re: Why does reading from /dev/urandom deplete entropy so much?

[Matt Mackall <mpm@selenic.com>]

On Sat, Dec 08, 2007 at 12:32:04PM -0500, Theodore Tso wrote:
> On Sat, Dec 08, 2007 at 02:37:57AM -0500, Jon Masters wrote:
> > > BTW, You may be better off using "uuidgen -t" to generate the UUID in
> > > the smolt RPM, since that will use 12 bits of randomness from
> > > /dev/random, plus the MAC, address and timestamp.  So even if there is
> > > zero randomness in /dev/random, and the time is January 1, 1970, at
> > > least the MAC will contribute some uniqueness to the UUID.
> > 
> > I haven't checked how uuidgen uses the MAC, but I would suggest that
> > that is not something Fedora should jump at doing - although it would
> > help ensure unique UUIDs, it also contributes to the tinfoil hat
> > responses that usually come up with things like smolt.
> 
> Huh?  What's the concern?  All you are submitting is a list of
> hardware devices in your system.  That's hardly anything sensitive....

Using MAC addresses -does- de-anonymize things though and presumably
anonymous collection is a stated goal.

-- 
Mathematics is the supreme nostalgia of our time.
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