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From: "Theodore Ts'o" <tytso@mit.edu>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David Wagner <daw-usenet@taverner.cs.berkeley.edu>,
	linux-kernel@vger.kernel.org
Subject: Re: no entropy and no output at /dev/random  (quick question)
Date: Mon, 29 Nov 2004 10:32:31 -0500	[thread overview]
Message-ID: <20041129153231.GA6060@thunk.org> (raw)
In-Reply-To: <E1CYIZ7-0005D3-00@gondolin.me.apana.org.au>

On Sun, Nov 28, 2004 at 05:29:45PM +1100, Herbert Xu wrote:
> David Wagner <daw@taverner.cs.berkeley.edu> wrote:
> > 
> > Yes, for almost all purposes, applications should use /dev/urandom,
> > not /dev/random.  (The names for these devices are unfortunate.)
> > Sadly, many applications fail to follow these rules, and consequently
> > /dev/random's entropy pool often ends up getting depleted much faster
> > than it has to be.
> 
> I agree with your conclusion that applications should use urandom.
> However, IIRC /dev/urandom depletes the entropy pool just as fast
> as /dev/random...

More specifically, most applications should use /dev/urandom to seed a
cryptographic random number generator which operates in userspace.  

						- Ted

  reply	other threads:[~2004-11-29 15:32 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-11-27  2:59 no entropy and no output at /dev/random (quick question) Javier Villavicencio
2004-11-27  4:38 ` Javier Villavicencio
2004-11-27 19:20   ` David Wagner
2004-11-28  6:29     ` Herbert Xu
2004-11-29 15:32       ` Theodore Ts'o [this message]
2004-11-30 12:49     ` Horst von Brand
2004-11-30 16:48       ` Javier Villavicencio
2005-01-07 19:17         ` Denis Vlasenko
2004-11-27 19:24   ` Jan Engelhardt
2004-11-27 19:22 ` Jan Engelhardt
2004-11-27 19:42   ` Andreas Steinmetz
2004-11-27 21:35     ` David Schwartz
2004-11-27 21:44       ` Jan Engelhardt
2004-11-29 22:47     ` Javier Villavicencio
2004-11-29 22:51   ` Javier Villavicencio

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