From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars Marowsky-Bree Subject: Re: Improving Data-At-Rest encryption in Ceph Date: Mon, 18 Jan 2016 13:21:16 +0100 Message-ID: <20160118122116.GH26972@suse.de> References: <20151215142304.GI31644@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mx2.suse.de ([195.135.220.15]:48705 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754754AbcARMVS (ORCPT ); Mon, 18 Jan 2016 07:21:18 -0500 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 4230BAD8D for ; Mon, 18 Jan 2016 12:21:16 +0000 (UTC) Content-Disposition: inline In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Ceph Development On 2016-01-18T09:05:58, Adam Kupczyk wrote: Hi Adam, > Plugging this into calculations I was using previously, gives us: > 1) Dmcrypt: > 1*0.36+2.5*0.64*3 =3D 5.16 bytes of crypto operations per byte of io = data. > 2) potential inside OSD encryption > 1*0.36+1*0.64 =3D 1 byte of crypto operations per byte of io data. >=20 > This further deepens my concern that crypto transformations may be > limit for performance. I see your concern, but my primary concern is not about performance, rather security. By not encrypting the entire OSD device, one becomes susceptible to metadata analysis (on the file store), data exposure, etc. (Plus, obviously, that the system devices need to be encrypted to avoid data leaks via logs, swap, coredumps etc.) It doesn't help my use case that your implementation is theoretically faster if it doesn't fit the threat scenario. I'd obviously be delighted to see this all sped up (and consume less power), but as long as the system is fast enough to encrypt at near-device speeds, this seems preferable. I'm not opposed to your implementation - I just couldn't sell it to my customers for data-at-rest encryption. Regards, Lars --=20 Architect Storage/HA SUSE Linux GmbH, GF: Felix Imend=F6rffer, Jane Smithard, Graham Norton,= HRB 21284 (AG N=FCrnberg) "Experience is the name everyone gives to their mistakes." -- Oscar Wil= de -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html