From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id D6FC51396D9 for ; Tue, 24 Oct 2017 12:01:26 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 636FE2BC085; Tue, 24 Oct 2017 12:01:21 +0000 (UTC) Received: from mail-pf0-x243.google.com (mail-pf0-x243.google.com [IPv6:2607:f8b0:400e:c00::243]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 08A892BC021 for ; Tue, 24 Oct 2017 12:01:20 +0000 (UTC) Received: by mail-pf0-x243.google.com with SMTP id b85so19497595pfj.13 for ; Tue, 24 Oct 2017 05:01:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:content-transfer-encoding; bh=R+Sg1yTsVqCag3/Bqu/41jsRgsqOHEwdjGr8DjG92aw=; b=DRO7mngQlGUFRaRQkWiNpt4iwUq2bXvttZZRX5wUitG9rIT/dsaTvW/Ju5LGHRvPhP +jCLLlRGEnhHkcgfbXsEFRHyfo1++5irFko29VNW/dxaf5yfjUzhUShRA1hrG1w8MPux LSrrxouc4Op3i1r54s5SPHB6ZbOVWKfG3V13RTKFMNXL0HfCZukmyd6RFCRqRAOa7hr1 ieSqBkYhmsVbxH/znV593N8Xh+ATdF+KCJzPxydNeiUyxjUuGpsl3iMoevYceq5UsiCq cbWe8qHt0LtF6xcv5culkEaI0VB3cY9yOtVZrnALtynxOawuzGUrRR2Vj3YKQ1wIkhog AQ3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:content-transfer-encoding; bh=R+Sg1yTsVqCag3/Bqu/41jsRgsqOHEwdjGr8DjG92aw=; b=U/RZUGBlm/xav2BvH6v3IwjdYLVnupAxohTeEaSXvhX4cMYpjf+tUNAq2J/Dk/gnUC UovTZNKj4fEsU1J/7fTYCaZ5Aq2zfT/8i2BCGdhbSufaRfW4jLXMO6mzydoe3heF/VXM 109Ab+pfHGSr5TWtny+5fp1SqroTObfTSHHg+BPv2xqDGvk3CSdkcfhi0mgHMKHQX6wb GvZ+uDTePX/S7fiu7Hq45Y5mcn/0lUgYH1EH3tmFs8uAuwdLIFm5Bxx33RXDmtdMTrLy dxiMQbzCb7tbbkuO7AG9U32DwTpnsUbOeYmHOgmSykz/6Mcp+ONZmboxM3YoIwsihb7W uT8g== X-Gm-Message-State: AMCzsaV2zt5xJW6hRFfhGduEpLrfCmGKvI5A+cQhlO9iCh4W64S4JT55 8HJZa4T4iKAlko1XeuNXQNjLU2J2aaJyrVkM6NTjgw== X-Google-Smtp-Source: ABhQp+SoD3oZE3Rsi9lPDprP3MF5I+jA2PGuMGy7q/OTzfaXbMA+CqKCGmBxKqYQQOoxJJyZjlJOfNinfQW/YufvzuU= X-Received: by 10.99.96.7 with SMTP id u7mr11987574pgb.183.1508846479472; Tue, 24 Oct 2017 05:01:19 -0700 (PDT) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-dev@lists.gentoo.org Reply-to: gentoo-dev@lists.gentoo.org MIME-Version: 1.0 Sender: freemanrich@gmail.com Received: by 10.100.155.67 with HTTP; Tue, 24 Oct 2017 05:01:18 -0700 (PDT) In-Reply-To: <18ecb9e4-a435-ce0b-6310-9f8896192e1c@gentoo.org> References: <1508440120.19870.14.camel@gentoo.org> <26AE424C-19DF-4059-A7DE-8ED6D605FF2C@gentoo.org> <1508817879.1688.6.camel@gentoo.org> <1508818272.1688.7.camel@gentoo.org> <18ecb9e4-a435-ce0b-6310-9f8896192e1c@gentoo.org> From: Rich Freeman Date: Tue, 24 Oct 2017 08:01:18 -0400 X-Google-Sender-Auth: JBHK5T-ew7lqcXPzLimf3ogE-GE Message-ID: Subject: Re: [gentoo-dev] Manifest2 hashes, take n+1-th: 3 hashes for the tie-breaker case To: gentoo-dev Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Archives-Salt: 8361ee8c-922d-4b81-aa56-76df5802e5e1 X-Archives-Hash: 40a7a376cdd960faecb9deca97e454d8 On Tue, Oct 24, 2017 at 4:21 AM, Pawe=C5=82 Hajdan, Jr. wrote: > On 24/10/2017 06:11, Micha=C5=82 G=C3=B3rny wrote: >> W dniu wto, 24.10.2017 o godzinie 06=E2=88=B604=E2=80=89+0200, u=C5=BCyt= kownik Micha=C5=82 G=C3=B3rny >> napisa=C5=82: >>> Three hashes don't give any noticeable advantage. If we want a diverse >>> construct, we take SHA3. SHA3 is slower than SHA2 + BLAKE2 combined, so >>> even with 3 threaded computation it's going to be slower. >> >> Oh, and most notably, the speed loss will be mostly visible to users. >> An attacker would have to compute the additional hashes only >> if the fastest hash already matched, i.e. rarely. Users will have to >> compute them all the time. > > I'm surprised to see bikeshedding about this, where the performance > argument was shown to be speculative. > > Consider clarifying what's the goal of this thread. > > It seemed like a relatively obvious cleanup / modernizing the set of > hash functions, and I'd still be supportive of that. > ++ IMO nothing really new has come up for the most part. People disagree on a few points, as is inevitable. The purpose of mailing lists isn't to keep reiterating the same points until there is unanimous agreement. Best to just move on. --=20 Rich