From owner-freebsd-security Wed Nov 17 20: 9: 3 1999 Delivered-To: freebsd-security@freebsd.org Received: from cairo.anu.edu.au (cairo.anu.edu.au [150.203.224.11]) by hub.freebsd.org (Postfix) with ESMTP id 88F0514FC2 for ; Wed, 17 Nov 1999 20:07:50 -0800 (PST) (envelope-from avalon@cairo.anu.edu.au) Received: (from avalon@localhost) by cairo.anu.edu.au (8.9.3/8.9.3) id PAA12677; Thu, 18 Nov 1999 15:08:35 +1100 (EST) From: Darren Reed Message-Id: <199911180408.PAA12677@cairo.anu.edu.au> Subject: Re: secure filesystem wiping To: drwho@xnet.com (Michael Maxwell) Date: Thu, 18 Nov 1999 15:08:35 +1100 (Australia/NSW) Cc: freebsd-security@freebsd.org In-Reply-To: <19991117213207.B21362@atlas.topquark.org> from "Michael Maxwell" at Nov 17, 1999 09:32:07 PM X-Mailer: ELM [version 2.5 PL1] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org In some mail from Michael Maxwell, sie said: > > On Thu, Nov 18, 1999 at 01:58:47PM +1100, Darren Reed wrote: > > alias rm "cp /dev/zero \!1; rm \!1" > > > > or something like that > > I don't know how truthful this is, but I have heard rumor that a skilled > data recovery expert (one with a very strong desire to see what you have > deleted), is capable of reading at least SOME data that has been written > over several times (something to do with extracting recognized patterns, > not really sure). > > U.S. government security "experts" state that one should write random > garbage over data no less than 17 times before it can be considered > secure. for the truely paranoid, the only secure way to delete files is destroying the physical medium used for storage. I know government departments do destroy media. simple over writes is not enough, be it 1, 17 or 17,000 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message