From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.saout.de ([127.0.0.1]) by localhost (mail.saout.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OZnmLj0h7HNy for ; Sun, 9 Dec 2012 13:25:47 +0100 (CET) Received: from mail-wg0-f46.google.com (mail-wg0-f46.google.com [74.125.82.46]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mail.saout.de (Postfix) with ESMTPS for ; Sun, 9 Dec 2012 13:25:47 +0100 (CET) Received: by mail-wg0-f46.google.com with SMTP id dr13so1195020wgb.1 for ; Sun, 09 Dec 2012 04:25:47 -0800 (PST) Message-ID: <50C48372.5030106@gmail.com> Date: Sun, 09 Dec 2012 13:26:26 +0100 From: =?ISO-8859-1?Q?Javier_Juan_Mart=EDnez_Cabez=F3n?= MIME-Version: 1.0 References: <20232.77.109.139.26.1355052014.squirrel@lavabit.com> In-Reply-To: <20232.77.109.139.26.1355052014.squirrel@lavabit.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [dm-crypt] (OT) Secure data wipe List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: dm-crypt@saout.de Yes is a lot offtopic, but could be useful for dmcrypt-users I don't know who has told you about the way of secure deleting a file but he is too wrong. When you delete something, you mark the physical blocks of the file as "usable for later", that is, moves into unallocated space, that could be allocated later. If you create a new file with the same name it gets free blocks to suit their needs but this doesn't mean that it will allocate the same physical blocks. The only method I know filesystem independent to destroy data is overwritting unallocated space several times with different patterns (to avoid recovering with microscopy). You can do the same overwritting allocated physical blocks of the file several times and this is what wipe does at my knowledge. I think the DoD published a paper about this you could check it. On 09/12/12 12:20, jugree@lavabit.com wrote: > Hello. > > How to securely delete data from a hard drive? Is it possible > without physical destruction? > > How to work with sensitive data if you're using swap? Is it enough > to run `swapoff', decrypt some data, encrypt it again, and run > `swapon'? > > Is it possible to securely delete a single file? I've heard that > you should create another file with the same name, write some data > to it, and delete it. > > This is a popular topic, but it's really hard to find any proofs. > > Can you suggest any books or papers on the subject? > > > _______________________________________________ dm-crypt mailing > list dm-crypt@saout.de > http://www.saout.de/mailman/listinfo/dm-crypt