[cryptography] urandom vs random

Aaron Toponce aaron.toponce at gmail.com
Sun Aug 18 16:41:04 EDT 2013


On Sat, Aug 17, 2013 at 12:48:12PM -0400, Sandy Harris wrote:
> On Fri, Aug 16, 2013 at 11:07 AM, Aaron Toponce <aaron.toponce at gmail.com> wrote:
> > The /dev/urandom device in the Linux kernel uses the Yarrow pseudo random
> > number generator when the entropy pool has been exhausted.
> 
> No, it doesn't, or at least did not last time I looked at the code, a few
> months ago. There are similaities, but also large differences.

Ah, my apologies. The FreeBSD implementation of a PRNG uses Yarrow. It appears
that http://lxr.linux.no/linux+v3.10.7/drivers/char/random.c is using SHA to
hash the contents of the entropy pool.

-- 
. o .   o . o   . . o   o . .   . o .
. . o   . o o   o . o   . o o   . . o
o o o   . o .   . o o   o o .   o o o
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 519 bytes
Desc: not available
URL: <http://lists.randombit.net/pipermail/cryptography/attachments/20130818/da298c65/attachment-0001.asc>


More information about the cryptography mailing list