From owner-freebsd-security@FreeBSD.ORG Sun Sep 23 15:17:01 2012 Return-Path: Delivered-To: freebsd-security@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id DD0D9106566B; Sun, 23 Sep 2012 15:17:01 +0000 (UTC) (envelope-from pawel@dawidek.net) Received: from mail.dawidek.net (garage.dawidek.net [91.121.88.72]) by mx1.freebsd.org (Postfix) with ESMTP id 9B94E8FC14; Sun, 23 Sep 2012 15:17:00 +0000 (UTC) Received: from localhost (89-73-195-149.dynamic.chello.pl [89.73.195.149]) by mail.dawidek.net (Postfix) with ESMTPSA id 52645F3E; Sun, 23 Sep 2012 17:15:51 +0200 (CEST) Date: Sun, 23 Sep 2012 17:17:06 +0200 From: Pawel Jakub Dawidek To: Mariusz Gromada Message-ID: <20120923151706.GN1454@garage.freebsd.pl> References: <20120918211422.GA1400@garage.freebsd.pl> <20120919231051.4bc5335b@gumby.homeunix.com> <20120920102104.GA1397@garage.freebsd.pl> <201209200758.51924.jhb@freebsd.org> <20120922080323.GA1454@garage.freebsd.pl> <20120922195325.GH1454@garage.freebsd.pl> <505E59DC.7090505@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="hXth9cGL35Nvpk4x" Content-Disposition: inline In-Reply-To: <505E59DC.7090505@gmail.com> X-OS: FreeBSD 10.0-CURRENT amd64 User-Agent: Mutt/1.5.21 (2010-09-15) Cc: Ben Laurie , freebsd-security@freebsd.org, RW , Jonathan Anderson , John Baldwin Subject: Re: Collecting entropy from device_attach() times. X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 23 Sep 2012 15:17:02 -0000 --hXth9cGL35Nvpk4x Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Sep 23, 2012 at 02:37:48AM +0200, Mariusz Gromada wrote: > W dniu 2012-09-22 21:53, Pawel Jakub Dawidek pisze: > > Mariusz, can you confirm my findings?=20 >=20 > Pawel, >=20 > Your conclusions can be easily confirmed by shape analysis of the EDF.=20 > Usually maximum quantile difference (called D-statistic) gives you a=20 > kind of overview, function shape gives you a strong feeling, p-value=20 > gives you a formal proof. > D-statistic values (your data): >=20 > 6bit: 0.33% > 7bit: 0.29% > 8bit: 0.27% > 9bit: 0.21% > 10bit: 6.34% > 11bit: 19.07% > 12bit: 54.80% >=20 > What I would say: increasing the number of bits from 6 to 9 does not=20 > affect distribution "uniformity", reaching the tenth bit results in=20 > sudden increase in the difference measure - the more bits, the more=20 > difference is observed. Distribution shape analysis for the 10th bit=20 > shows non-linear function. Lack of "randomness" in the quntile=20 > difference curve - chart shows completely lack of noise (pure=20 > functional relation). These are very strong indicators that starting=20 > from 10th bit distribution was changed and is no longer uniform. >=20 > To formally confirm above conclusion for i.e. 5% significance level,=20 > which means that confidence level is 95%, I need some extra data=20 > regarding sample sizes. Please pass to me number of collected=20 > observations in each 6-12 bit experiment. Total number of observations was 162833. --=20 Pawel Jakub Dawidek http://www.wheelsystems.com FreeBSD committer http://www.FreeBSD.org Am I Evil? Yes, I Am! http://tupytaj.pl --hXth9cGL35Nvpk4x Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iEYEARECAAYFAlBfJ/IACgkQForvXbEpPzQJ+wCbBzLCJZkjhz6vQr0MuBiXXEqT HiIAnj9DLk6BvR+JiGmlUOviNaKY5Rhk =DrJs -----END PGP SIGNATURE----- --hXth9cGL35Nvpk4x--