From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.6 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 0290A1F597 for ; Fri, 3 Aug 2018 02:57:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727403AbeHCEvS (ORCPT ); Fri, 3 Aug 2018 00:51:18 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:43260 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726256AbeHCEvR (ORCPT ); Fri, 3 Aug 2018 00:51:17 -0400 Received: by mail-pg1-f196.google.com with SMTP id d17-v6so2124170pgv.10 for ; Thu, 02 Aug 2018 19:57:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=JJE6+NgvcOI/OyFHfEuTQ7PNX5hWS/Jl0yHIhOUxl6Q=; b=YXYD395uQH7Grw51XV5jrkLf0KoM/SQwfxopcmU22soA2L8/pKLxjfMzTegJGs58b6 /KBKk2EW24nu+kQFU7oSmpUxRAB74LZhM/CmOF5TeEAO3Vgff4NLJUA79Ay1ynAo/dnU 8McSI94nsUqvc4EmrvT9EKCNhHIlNBpoSqYwW0yhAzMrqp0Zuqd60EcSc5agckp3WVS+ ZJIbMC00tpwxS8xl5spE5ciehj5NdOWf7MotMq4wdbrQBTxU7DI6uWng948xdXcVtSuK EQwJIzvOULHOBWIN9qZREwecUHaemEsdk3dllSCmAuzmEdQ7NPzr70hU7Ujd5skWAsp9 ebMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=JJE6+NgvcOI/OyFHfEuTQ7PNX5hWS/Jl0yHIhOUxl6Q=; b=N3fnOavpnoiNZWTh7t1J/U+SKeOj7Gu462znqyYedDWFzp+VCP37RCm5uD4M+YkDLd sO3BB4XmcFXdRFN1ONpVQGLlNs59BYud4ea/gx9irjDDhkNx2amghNc1GVI4CeAYQ4Bw ejsmGICwCxLc3uDBvkIiw08uSg/pjp4wTvOSSTTo4Vb6L7gfn7KPlkHC/Jwjc6cbHLuT UyC+6Kj6NVHMteAzy9CHR+bkbxhns5aJsqJARZfChJah7dEWFHKzkmAncGab7LAr1ylT hrj1KRU0iDy3Nb5vLGoOE8xmT37NyWfW/zoBHge5gcpAWl/irCl13jc7B5bsfnAruwq+ 3c8w== X-Gm-Message-State: AOUpUlGTMNjI5ScUMrlynVsX0Iix4Sta7CnEBZIbM7BpCnpbZflQnjAD 49lZP+hi9L86VA7ytPpCVZADlSCu X-Google-Smtp-Source: AAOMgpevc+NLXopDZWkKLpOfry3zeg6V/5p3KvCA/7Z2LvajNEMvrPGzcd2fkxPfkYcWNSOeKPeYfg== X-Received: by 2002:a63:e206:: with SMTP id q6-v6mr1866244pgh.223.1533265032159; Thu, 02 Aug 2018 19:57:12 -0700 (PDT) Received: from aiede.svl.corp.google.com ([2620:0:100e:422:4187:1d6c:d3d6:9ce6]) by smtp.gmail.com with ESMTPSA id 1-v6sm5888348pfm.145.2018.08.02.19.57.11 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 02 Aug 2018 19:57:11 -0700 (PDT) Date: Thu, 2 Aug 2018 19:57:09 -0700 From: Jonathan Nieder To: Dan Shumow Cc: Johannes Schindelin , "brian m. carlson" , Junio C Hamano , Linus Torvalds , Edward Thomson , Git Mailing List , demerphq , Adam Langley , "keccak@noekeon.org" Subject: Re: Hash algorithm analysis Message-ID: <20180803025709.GD197924@aiede.svl.corp.google.com> References: <20180609205628.GB38834@genre.crustytoothpaste.net> <20180609224913.GC38834@genre.crustytoothpaste.net> <20180611192942.GC20665@aiede.svl.corp.google.com> <20180720215220.GB18502@genre.crustytoothpaste.net> <20180724190136.GA5@0f3cdde9c159> <20180724221008.GI18502@genre.crustytoothpaste.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Hi Dan, Dan Shumow wrote: [replying out of order for convenience] > However, I agree with Adam Langley that basically all of the > finalists for a hash function replacement are about the same for the > security needs of Git. I think that, for this community, other > software engineering considerations should be more important to the > selection process. Thanks for this clarification, which provides some useful context to your opinion that was previously relayed by Dscho. [...] > So, as one of the coauthors of the SHA-1 collision detection code, I > just wanted to chime in and say I'm glad to see the move to a longer > hash function. Though, as a cryptographer, I have a few thoughts on > the matter that I thought I would share. > > I think that moving to SHA256 is a fine change, and I support it. More generally, thanks for weighing in and for explaining your rationale. Even (especially) having already made the decision, it's comforting to hear a qualified person endorsing that choice. Sincerely, Jonathan