From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755139AbXLDRAj (ORCPT ); Tue, 4 Dec 2007 12:00:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754265AbXLDRA0 (ORCPT ); Tue, 4 Dec 2007 12:00:26 -0500 Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:59379 "EHLO the-village.bc.nu" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753959AbXLDRAZ (ORCPT ); Tue, 4 Dec 2007 12:00:25 -0500 Date: Tue, 4 Dec 2007 16:55:02 +0000 From: Alan Cox To: "Ray Lee" Cc: "Adrian Bunk" , "Matt Mackall" , "Marc Haber" , linux-kernel@vger.kernel.org Subject: Re: Why does reading from /dev/urandom deplete entropy so much? Message-ID: <20071204165502.0a8f695e@the-village.bc.nu> In-Reply-To: <2c0942db0712040854u17a830b9see663742b2716457@mail.gmail.com> References: <20071204114125.GA17310@torres.zugschlus.de> <20071204161811.GB15974@stusta.de> <2c0942db0712040854u17a830b9see663742b2716457@mail.gmail.com> X-Mailer: Claws Mail 2.10.0 (GTK+ 2.10.14; i386-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > 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