From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org (plane.gmane.org [80.91.229.3]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.server123.net (Postfix) with ESMTPS for ; Sun, 8 Feb 2015 15:06:58 +0100 (CET) Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1YKSVk-0007gb-Q1 for dm-crypt@saout.de; Sun, 08 Feb 2015 15:06:56 +0100 Received: from ip4d151e07.dynamic.kabel-deutschland.de ([77.21.30.7]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sun, 08 Feb 2015 15:06:56 +0100 Received: from for-gmane by ip4d151e07.dynamic.kabel-deutschland.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sun, 08 Feb 2015 15:06:56 +0100 From: "U.Mutlu" Date: Sun, 08 Feb 2015 15:06:49 +0100 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Subject: [dm-crypt] inner workings of block mode encryption List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: dm-crypt@saout.de Hi, I'm interessted in the inner workings of encrypting block devices like the encrypted volumes created with the cryptsetup tool. Let's say a file of size 200K is stored on an encrypted ext2 filesystem. How is the enrcyption key applied to it? I guess the password is used only for accessing/mounting the volume, and the key is only a starting value (ie. a "seed") for the underlying cipher. Since in these cases usually a blockwise operating cipher is used, that means that the file will be encrypted of course blockwise, for example in blocks of 32 bytes. Now the question: are the blocks of that file all encrypted using the same one key? Or does a kind of "streaming" or HMAC get used for the subsequent blocks of the file? -- TIA Uenal