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

From:  Alan Cox <alan-AT-lxorguk.ukuu.org.uk>
To:  "Ray Lee" <ray-AT-madrabbit.org>
Subject:  Re: Why does reading from /dev/urandom deplete entropy so much?
Date:  Tue, 4 Dec 2007 16:55:02 +0000
Message-ID:  <20071204165502.0a8f695e@the-village.bc.nu>
Cc:  "Adrian Bunk" <bunk-AT-kernel.org>, "Matt Mackall" <mpm-AT-selenic.com>, "Marc Haber" <mh+linux-kernel-AT-zugschlus.de>, linux-kernel-AT-vger.kernel.org
Archive-link:  Article, Thread

> cryptographically strong stream it'll provide when /dev/random is
> tapped? In principle, this'd leave more entropy available for
> applications that really need it, especially on platforms that don't
> generate a lot of entropy in the first place (servers).


As reported about a month ago, the evidence is that the /dev/random
stream is not cryptographically strong. Collecting uuids generated from
the kernel uuid random generator from the random generator in the kernel
shows abnormal patterns of duplicates.

Alan
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