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

Mike McGrath
2007-12-08T17:41:18Z

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....
>

We actually had a very vocal minority about all of that which ended up
putting us in the unfortunate position of generating a random UUID
instead of using a hardware UUID from hal :-/

-Mike