From owner-freebsd-questions Thu Nov 18 13:27:48 1999 Delivered-To: freebsd-questions@freebsd.org Received: from cdc01.cleveland.dynacs.com (cleveland.dynacs.com [216.28.130.3]) by hub.freebsd.org (Postfix) with ESMTP id 684F015508 for ; Thu, 18 Nov 1999 13:27:43 -0800 (PST) (envelope-from Timothy.A.Musson@grc.nasa.gov) Received: from ssdmail.aero2k1.net (IDENT:root@node018.cleveland.dynacs.com [216.28.130.18]) by cdc01.cleveland.dynacs.com (8.9.2/8.9.2) with ESMTP id QAA01328; Thu, 18 Nov 1999 16:37:03 -0500 (EST) Received: from kitt (sams22.lerc.nasa.gov [139.88.30.245]) by ssdmail.aero2k1.net (8.9.2/8.9.2) with SMTP id QAA22169; Thu, 18 Nov 1999 16:08:58 -0500 (EST) Message-Id: <199911182108.QAA22169@ssdmail.aero2k1.net> X-Sender: tmusson@ssdmail.aero2k1.net X-Mailer: QUALCOMM Windows Eudora Pro Version 4.0.2 Date: Thu, 18 Nov 1999 16:31:41 -0500 To: Jonathon McKitrick From: "Timothy A. Musson" Subject: Re: secure filesystem wiping Cc: questions@FreeBSD.ORG In-Reply-To: References: <99Nov19.074604est.40354@border.alcanet.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG It *is* possible to write back garbage or 0xFF. The problem is that no matter how much you write over it, if someone *really* wants your data, they can get it (with physical access to the drive, of course). If destroying the drive is a problem, you either need to re-phrase the question to be, "what is the most secure way to obliterate files on FreeBSD, that still leaves the drive/filesystem intact?", or convince yourself to be happy with the level of security you get with over-writing. At 04:04 PM 11/18/99 , you wrote: >On Fri, 19 Nov 1999, Peter Jeremy wrote: > >>This isn't technically possible. You can't securely wipe data from a >>disk using the disks own R/W head/electronics (which is the only way >>to preserve intact files). > >Why isn't it possible to read unallocated sectors and write back sectors >full of garbage, or 0xFF? >-jm > > > >To Unsubscribe: send mail to majordomo@FreeBSD.org >with "unsubscribe freebsd-questions" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message