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From: Oliver Neukum <oliver@neukum.name>
To: Marco Colombo <marco@esi.it>, "Theodore Ts'o" <tytso@mit.edu>
Subject: Re: [PATCH] (0/4) Entropy accounting fixes
Date: Mon, 19 Aug 2002 12:25:22 +0200
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Am Montag, 19. August 2002 12:15 schrieb Marco Colombo:
> On Mon, 19 Aug 2002, Theodore Ts'o wrote:
>
> [...]
>
> > P.S.  /dev/urandom should probably also be changed to use an entirely
> > separate pool, which then periodically pulls a small amount of entropy
> > from the priamry pool as necessary.  That would make /dev/urandom
> > slightly more dependent on the strength of SHA, while causing it to
> > not draw down as heavily on the entropy stored in /dev/random, which
> > would be a good thing.
>
> Shouldn't it be moved to userpace, instead? Pulling a small amount
> of entropy from /dev/random can be done in userspace, too. And the

1. You create a problem for in kernel users of random numbers.
2. You forgo the benefit of randomness by concurrent access to /dev/urandom
3. You will not benefit from hardware random number generators as easily.

> application could choose *how often* and *how many* bits to pull.

If you really care, you can implement this for /dev/urandom, too.

	Regards
		Oliver

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