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From: Andrea Arcangeli <andrea@suse.de>
To: linux-os@analogic.com
Cc: "Patrick J. LoPresti" <patl@curl.com>,
	Linux kernel <linux-kernel@vger.kernel.org>
Subject: Re: /dev/random vs. /dev/urandom
Date: Tue, 11 Jan 2005 15:38:54 +0100	[thread overview]
Message-ID: <20050111143854.GO26799@dualathlon.random> (raw)
In-Reply-To: <Pine.LNX.4.61.0501100735210.19253@chaos.analogic.com>

On Mon, Jan 10, 2005 at 07:41:02AM -0500, linux-os wrote:
> one could AND with 0 and show that all randomness has been removed.

Zero removes all bits so it's a special case.

As long as 1 bit is left coming from /dev/*random and not your
application, you're guaranteed that single bit to be random (since you
didn't mask it).

It's like if I read 100 bytes from /dev/random and then I truncate the
last 99 and it'll be as random as reading a single byte. Random means
all single bits are random too, not only the entire bytes.

      parent reply	other threads:[~2005-01-11 14:38 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-01-07 19:05 /dev/random vs. /dev/urandom Ron Peterson
2005-01-07 19:16 ` Paulo Marques
2005-01-07 19:24 ` Chris Friesen
2005-01-07 19:26 ` Florian Weimer
2005-01-07 19:27 ` linux-os
2005-01-07 19:40 ` Robert Love
2005-01-07 20:50   ` Ron Peterson
2005-01-07 21:39 ` Andries Brouwer
2005-01-07 22:39   ` linux-os
2005-01-07 17:55     ` Michal Schmidt
2005-01-07 23:29     ` Andries Brouwer
2005-01-08 17:34     ` Patrick J. LoPresti
2005-01-10 12:41       ` linux-os
2005-01-10 13:03         ` Paulo Marques
2005-01-10 14:39           ` Felipe Alfaro Solana
2005-01-10 15:13         ` Patrick J. LoPresti
2005-01-10 19:24         ` David Schwartz
2005-01-11 14:38         ` Andrea Arcangeli [this message]

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