From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:49987 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753856AbaLATef (ORCPT ); Mon, 1 Dec 2014 14:34:35 -0500 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1XvWjx-0006yl-5P for linux-btrfs@vger.kernel.org; Mon, 01 Dec 2014 20:34:33 +0100 Received: from 50.245.141.77 ([50.245.141.77]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 01 Dec 2014 20:34:33 +0100 Received: from eternaleye by 50.245.141.77 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 01 Dec 2014 20:34:33 +0100 To: linux-btrfs@vger.kernel.org From: Alex Elsayed Subject: Re: [RFC PATCH] Btrfs: add sha256 checksum option Date: Mon, 01 Dec 2014 11:34:19 -0800 Message-ID: References: <1416806586-18050-1-git-send-email-bo.li.liu@oracle.com> <20141125163905.GJ26471@twin.jikos.cz> <547C618C.8020201@gmail.com> <547CA870.9040904@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Sender: linux-btrfs-owner@vger.kernel.org List-ID: Alex Elsayed wrote: > * He was comparing CRC32 (a 32-bit non-cryptographic hash, *via the Crypto > API*) against SHA-1 (a 128-bit cryptographic hash, via the Crypto API), > and SHA-1 _still_ won. CRC32 tends to beat the pants off 128-bit non- > cryptographic hashes simply because those require multiple registers to > store the state if nothing else; which makes this a rather strong argument > that _hardware matters a heck of a lot_, quite possibly _more_ than the > algorithm. Ah, correction - it seems he was comparing his own implementations, rather than the Crypto API ones - but the points still hold, seeing as the Crypto API does provide both algorithms.