From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2A4BC04AB4 for ; Thu, 16 May 2019 08:20:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D15220818 for ; Thu, 16 May 2019 08:20:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726393AbfEPIUu (ORCPT ); Thu, 16 May 2019 04:20:50 -0400 Received: from mx2.suse.de ([195.135.220.15]:56526 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726347AbfEPIUu (ORCPT ); Thu, 16 May 2019 04:20:50 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D77C6AE1F; Thu, 16 May 2019 08:20:48 +0000 (UTC) Date: Thu, 16 May 2019 10:20:48 +0200 From: Johannes Thumshirn To: Nikolay Borisov Cc: Paul Jones , "dsterba@suse.cz" , David Sterba , Linux BTRFS Mailinglist Subject: Re: [PATCH 00/17] Add support for SHA-256 checksums Message-ID: <20190516082048.GC3922@x250.microfocus.com> References: <20190510111547.15310-1-jthumshirn@suse.de> <20190515172720.GX3138@twin.jikos.cz> <4db81b36-a2ac-f954-abad-f020e42120ca@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4db81b36-a2ac-f954-abad-f020e42120ca@suse.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, May 16, 2019 at 11:16:38AM +0300, Nikolay Borisov wrote: > It is labelled non-cryptographic, and is not meant to avoid intentional > collisions (same digest for 2 different messages), or to prevent > producing a message with predefined digest. > > This doesn't disqualify it, however we need to be aware its limitations. > Perhahps it could be used as a replacement for crc32c but definitely not > as secure crypto hash. Agreed, but David's plan was to have 3 hashes and xx seems like a good fit for the 3rd fast, stronger than crc32c but not cryptographically secure option. I'll be looking into it for v3. -- Johannes Thumshirn SUSE Labs Filesystems jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850