IETF Logo Mail Archive

[dmarc-ietf] Re: New Tack - Learning from ARC Experiment

John R Levine <johnl@ietf.email> Sat, 16 May 2026 17:27 UTC

Return-Path: <johnl@ietf.email>
X-Original-To: dmarc@mail2.ietf.org
Delivered-To: dmarc@mail2.ietf.org
Received: from localhost (localhost [127.0.0.1]) by mail2.ietf.org (Postfix) with ESMTP id EF4C5EF4B187 for <dmarc@mail2.ietf.org>; Sat, 16 May 2026 10:27:13 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ietf.org; s=ietf1; t=1778952433; bh=4pIf0zslc7vVkgniQHJUFKc/XWBSaUHvTaHK0BjEDY8=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=lOYESwdgo++hhSTXNn54V5Gt17rMA3ASSHG18nh17/SdCsbV+7GHp7poCSbCJkH4f DV8mnwOXj92FlIO/ZgcprgLLNP2THcSLj9eIbiNY7YYTtqWx1pIVu1vbEew39I7gV/ gMIe7TalDaSsq/3pmZj6hH22mcTE9ybNZ1NmBnVM=
X-Virus-Scanned: amavisd-new at ietf.org
X-Spam-Flag: NO
X-Spam-Score: -4.401
X-Spam-Level:
X-Spam-Status: No, score=-4.401 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: mail2.ietf.org (amavisd-new); dkim=pass (2048-bit key) header.d=iecc.com header.b="d8dD4QQ5"; dkim=pass (2048-bit key) header.d=ietf.email header.b="Jgfi0NWN"
Received: from mail2.ietf.org ([166.84.6.31]) by localhost (mail2.ietf.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 67Mo5w7sk6WS for <dmarc@mail2.ietf.org>; Sat, 16 May 2026 10:27:13 -0700 (PDT)
Received: from gal.iecc.com (gal.iecc.com [IPv6:2001:470:1f07:1126:0:43:6f73:7461]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail2.ietf.org (Postfix) with ESMTPS id 6FF83EF4B181 for <dmarc@ietf.org>; Sat, 16 May 2026 10:27:13 -0700 (PDT)
Received: (qmail 63986 invoked from network); 16 May 2026 17:27:07 -0000
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=iecc.com; h=date:message-id:from:to:cc:subject:in-reply-to:references:mime-version:content-type; s=f9f06a08a8eb.k2605; t=1778952417; x=1779298017; bh=4pIf0zslc7vVkgniQHJUFKc/XWBSaUHvTaHK0BjEDY8=; b=d8dD4QQ5Tz8Q3tg+3AQIVOVv8vPBM2Zqk/JjVK3MPEMDx06A5E6ZBx/QhM9j6mYVB7XMyxuppEEdXVjoiHwBsd9c4vSOYe1L4nr9j5Dsc5qNvSI28Oi9lvF2c987ZXAxkD/DGFp92wgdE0l3V9MIJ0guc17jI2J4VhvpH97LuGuY6S6xAo3ygTsZx85ZvkGwdwiDVy8cPX10dWURN3BGqDruDrDOfU92rpPEr8PwapsnRIgEsUBcYKqdpff8q98AR9WdEOZJkCLFzyc4Dmgv4JiOVGk2eKWGhj1W77SGInaLdKYEKr+lQcsOk6aAmCU4f/WjJ59KhYdumTgr41Kz4w==
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed; d=ietf.email; h=date:message-id:from:to:cc:subject:in-reply-to:references:mime-version:content-type; s=f9f06a08a8eb.k2605; bh=4pIf0zslc7vVkgniQHJUFKc/XWBSaUHvTaHK0BjEDY8=; b=Jgfi0NWNXmpuPTb5lKuzupswOkSxMFod0HtADok1/OVnAsFY93nA9jdkOk7RjhJs/JhZtpQFmseFoeOj9UYSRqbgsN317qD3KDNeCOzLVk2wB2Q+IWnx4NgzStslVouSci4QmBPCzIoS/58y5o+7Pu9cJBmBjssbGHtX922X8bVrXQxy+ye+0SpUmvqBUYYo7oYFH8f5k0vEgMM1c4D+LoA8AQWKessTLzqykZwpipztODJseRFM/v9uF9RQgJSD7ZKLOIM7QOGptFKU1VdOo5TGwxU61VuG7YbaCFciU8sAatFNqvVGfkpDcHB8PqMYpdrattxR4ZTCDXdHQtj73Q==
Received: from ary.qy ([IPv6:2001:470:1f07:1126:0:78:696d:6170]) by imap.iecc.com ([IPv6:2001:470:1f07:1126:0:78:696d:6170]) with ESMTPS (TLS1.3 ECDHE-RSA CHACHA20-POLY1305 AEAD) via TCP6; 16 May 2026 17:27:06 -0000
Received: by ary.qy (Postfix, from userid 501) id 5E05C10AA654F; Sat, 16 May 2026 13:27:05 -0400 (EDT)
Received: from localhost (localhost [127.0.0.1]) by ary.qy (Postfix) with ESMTP id BD06B10AA6530; Sat, 16 May 2026 13:27:05 -0400 (EDT)
Date: Sat, 16 May 2026 13:27:05 -0400
Message-ID: <924adfb1-22db-d750-9169-9d88f23e3728@ietf.email>
From: John R Levine <johnl@ietf.email>
To: Alessandro Vesely <vesely@tana.it>, "Murray S. Kucherawy" <superuser@gmail.com>
In-Reply-To: <343588b1-1238-4195-846f-eecd185b682b@tana.it>
References: <IA1PR12MB653180F1812B340891121599B3382@IA1PR12MB6531.namprd12.prod.outlook.com> <2bafa613-1861-4dd1-8e15-e400b73ab50b@tana.it> <CAL0qLwb5ED=o+=OGrGr=eW4nX-A9DR4BSDVSkzsNtDr0kShyqA@mail.gmail.com> <20260512194027.262BE1099FC6B@ary.local> <274bc4f7-9fb3-4f1c-b202-0e13b17ea465@tana.it> <CAL0qLwY=Jyu5dhQfd94fWdJ3X=hp0dAf9a2Gf65VRNA8Ga9uaA@mail.gmail.com> <d68908dc-4032-420f-b89c-749a75cde2c0@tana.it> <3e73dc4a-1c7c-44f4-0910-9bc261ff46a3@ietf.email> <343588b1-1238-4195-846f-eecd185b682b@tana.it>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; format="flowed"
Message-ID-Hash: HT537STT67L7FOQLFUU2ZZQHKREVKCVI
X-Message-ID-Hash: HT537STT67L7FOQLFUU2ZZQHKREVKCVI
X-MailFrom: johnl@ietf.email
X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-dmarc.ietf.org-0; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header
CC: dmarc@ietf.org
X-Mailman-Version: 3.3.9rc6
Precedence: list
Subject: [dmarc-ietf] Re: New Tack - Learning from ARC Experiment
List-Id: "Domain-based Message Authentication, Reporting, and Compliance (DMARC)" <dmarc.ietf.org>
Archived-At: <https://mailarchive.ietf.org/arch/msg/dmarc/qKF76MBsUpW5q9pmv9_Az1xbx78>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dmarc>
List-Help: <mailto:dmarc-request@ietf.org?subject=help>
List-Owner: <mailto:dmarc-owner@ietf.org>
List-Post: <mailto:dmarc@ietf.org>
List-Subscribe: <mailto:dmarc-join@ietf.org>
List-Unsubscribe: <mailto:dmarc-leave@ietf.org>

On Sat, 16 May 2026, Alessandro Vesely wrote:
>
> Mainly to understand whether the ARC experiment revealed a missing
> authorization semantic.
>
> ARC can preserve authentication results across intermediaries, but that
> is not quite the same thing as establishing whether a mediation path is
> acceptable.

It can't even do that, since you can't tell whether links in the ARC chain 
beyond the most recent are real or fake.  That's why DKIM2 puts a 
signature on each hop, so the recipient can verify them all.

I'm still not seeing any use in distracting DKIM2 with ARC stuff, nor in 
spending more time trying to rescusciatate ARC.

R's,
John

v2.46.0 | Report a Bug | By Email | System Status