From owner-freebsd-questions@FreeBSD.ORG Fri Jan 18 18:23:40 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A7BD216A419 for ; Fri, 18 Jan 2008 18:23:40 +0000 (UTC) (envelope-from fbsd06+SI=fd0fe4ff@mlists.homeunix.com) Received: from turtle-out.mxes.net (turtle-out.mxes.net [216.86.168.191]) by mx1.freebsd.org (Postfix) with ESMTP id 67FE913C467 for ; Fri, 18 Jan 2008 18:23:40 +0000 (UTC) (envelope-from fbsd06+SI=fd0fe4ff@mlists.homeunix.com) Received: from mxout-04.mxes.net (mxout-04.mxes.net [216.86.168.179]) by turtle-in.mxes.net (Postfix) with ESMTP id AE817164679 for ; Fri, 18 Jan 2008 12:58:36 -0500 (EST) Received: from gumby.homeunix.com. (unknown [87.81.140.128]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.mxes.net (Postfix) with ESMTP id 22338D05AB for ; Fri, 18 Jan 2008 12:58:34 -0500 (EST) Date: Fri, 18 Jan 2008 17:58:31 +0000 From: RW To: freebsd-questions@freebsd.org Message-ID: <20080118175831.72929086@gumby.homeunix.com.> In-Reply-To: <478F8980.1090301@highperformance.net> References: <478F0D5A.9090107@highperformance.net> <20080117081414.GB12470@draenor.org> <478F1049.3000706@boosten.org> <20080117083837.GC12470@draenor.org> <20080117094332.K1563@wojtek.tensor.gdynia.pl> <20080117090210.GD12470@draenor.org> <478F8980.1090301@highperformance.net> X-Mailer: Claws Mail 3.0.2 (GTK+ 2.12.5; i386-portbld-freebsd7.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: Gutman Method on Empty Space X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Jan 2008 18:23:40 -0000 On Thu, 17 Jan 2008 08:59:44 -0800 "Jason C. Wells" wrote: > Gutmann method might be excessive but any software that uses it shows > a seriousness about security. Gutmann himself regards the continued use of his method as "Voodoo" Gutmann's paper was about wiping the kind of disks that were being disposed of in 1996. The write patterns used in his method are specific to drives that were already out of production at the time. For drives that were in production, a few random passes are the best that can be done. His opinion now is that with modern drive technologies the chances of recovering anything useful are virtually zero. I've never heard any indication that agencies like the FBI can do it, or that commercial companies can provide such a service - at any price. If you are serious about security, one or two passes from /dev/random to the device are fine. If you are paranoid about what the NSA might be able to do, buy a pickaxe.