From: Sebastian Andrzej Siewior Subject: Re: [PATCH] dm-crypt: disable block encryption with arc4 Date: Tue, 9 Feb 2010 22:12:38 +0100 Message-ID: <20100209211238.GC21548@Chamillionaire.breakpoint.cc> References: <20100209073718.GA17612@gondor.apana.org.au> <20100209145705.GA20421@Chamillionaire.breakpoint.cc> <20100209204519.GC26258@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Cc: Mikulas Patocka , mbroz@redhat.com, linux-crypto@ml.breakpoint.cc, dm-devel@redhat.com, agk@redhat.com, linux-crypto@vger.kernel.org To: Herbert Xu Return-path: Received: from Chamillionaire.breakpoint.cc ([85.10.199.196]:55901 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753111Ab0BIVMm (ORCPT ); Tue, 9 Feb 2010 16:12:42 -0500 Content-Disposition: inline In-Reply-To: <20100209204519.GC26258@gondor.apana.org.au> Sender: linux-crypto-owner@vger.kernel.org List-ID: * Herbert Xu | 2010-02-10 07:45:19 [+1100]: >> Herbert, what happend to the "check for streamcipher" idea you had? Is >> it gone? On the other hand it wouldn't be probably that bad to have a > >Well again whether that should be done is up to the dm-crypt >maintainers. Milan liked that afaik. >> seprate interface to grab a block cipher _or_ a stream cipher. So > >Just because something isn't a stream cipher doesn't mean that >it is safe for disk encryption. People simply shouldn't be using >random algorithms for disk encryption. > >> I can't imaging how you want to fix arc4 that it will work in dm-crypt. > >I thought I've explained this before. Just turn it into a blkcipher >and add IV. I beg your pardon. I probably mixed things up. >> The algorithm relies more or less on the fact that it envolves itself >> during processing of data. > >This is no different to any stream cipher. Sure. So we fix arc4 and don't play mother . Okay I will into this :) > >Cheers, Sebastian