Return-Path: X-Original-To: dmarc@ietfa.amsl.com Delivered-To: dmarc@ietfa.amsl.com Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C124B3A0C4A for ; Sun, 19 Jul 2020 17:52:49 -0700 (PDT) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -2.098 X-Spam-Level: X-Spam-Status: No, score=-2.098 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, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, NICE_REPLY_A=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 21RK8rRFVJj9 for ; Sun, 19 Jul 2020 17:52:48 -0700 (PDT) Received: from mail-oi1-x232.google.com (mail-oi1-x232.google.com [IPv6:2607:f8b0:4864:20::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 536953A0C49 for ; Sun, 19 Jul 2020 17:52:48 -0700 (PDT) Received: by mail-oi1-x232.google.com with SMTP id k4so13144042oik.2 for ; Sun, 19 Jul 2020 17:52:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language; bh=KTolY6UtiueKpQqOPQK0bG3fnBx7ULmX+jv0aw3a+QU=; b=DexPU6XI/g2VdV5U9JzkJqAFKRX82drVWr2kYlt27OJaPSNxsj/l7KQ3UqW6Rax1iI nVP5ds61kvSh75ClzOHvRKws0GbKmWgZmZ7q2IEoEPVO4NIsmwYSl00xXmvFj9ZC3Qkd NBz0EP3mzdHrLnz32NsthSJQEr4Xmi2XekVvqcS3Tgz/j4XeCU2fdIVAhHMik5upbZYP 5C99laBEuqCY8B5PN+FEw0GnPUEv9AmOq4hAGfRCQVGWLXtv8/aDcqkknvm4bMEqbxjM DyMvU+pOf2+wXZdTpTG2KBN7ieLDMeNz1Gm3ILhyQDKQ20SnluJht6xpPiH1wLuP+NZe U0+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language; bh=KTolY6UtiueKpQqOPQK0bG3fnBx7ULmX+jv0aw3a+QU=; b=juRaq8g/PSi72QrKwb8xpLjtsRQe5+Kt8mb57UwukZprhzKJ/IGMYAKHke3qK6ESWu 7qAvS1519AWmuIZzgD6j0Fw/qdLUgzlqVmSQXwU1B8/B15EVfp5EU9bK/GhxdOvYYEVB wWiYb8EvvvsVpZuktzXt/BNvgw7IXe8/Dg242Ldp5BM/WQcsRSTYhpGl5ap+Ya3v+DlB RIfv/Dy+fyV91JEKhXZur1S2KEoDshKPLbuGwwWC6QGhnE8Ai8Ks3IgEY+BRihbOu7Bh VhCyhUVpIe57xOVc0GdRczJHGnuzmlQ6+gfcpJcBJH9roakyJosn2V3ICgw6Gw5C+9Ip yn9Q== X-Gm-Message-State: AOAM533f+2b2robzA0ZP9zWPafWWtr9o50gMQuuTVfy0ryG9hKlx+SIL ViLp5TMM/UZsPfju9p0X8rfNFx3yIew= X-Google-Smtp-Source: ABdhPJxn2eevwU4iP1tQ7DYiMJE2orBqIuDdBPg3t4G+MwoUH++cjKJs4vizxB49IO1J84FSklZ3mA== X-Received: by 2002:aca:524c:: with SMTP id g73mr15635298oib.150.1595206367276; Sun, 19 Jul 2020 17:52:47 -0700 (PDT) Received: from ?IPv6:2600:1700:a3a0:4c80:fc69:4fcf:5c0d:166? ([2600:1700:a3a0:4c80:fc69:4fcf:5c0d:166]) by smtp.gmail.com with ESMTPSA id c7sm3233131otm.19.2020.07.19.17.52.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 19 Jul 2020 17:52:46 -0700 (PDT) To: "Murray S. Kucherawy" Cc: IETF DMARC WG References: <20200717210053.674D61D2C431@ary.qy> <8efcf71c-f841-46a4-10b7-feb41a741405@gmail.com> <381c7792-5bd8-a1be-6b93-b7df015a2333@gmail.com> From: Dave Crocker Message-ID: <0f93b44d-7a5b-996e-b260-75f6f1de0234@gmail.com> Date: Sun, 19 Jul 2020 17:52:44 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/alternative; boundary="------------327D9A1A8416A8ACFBF3BE39" Content-Language: en-US Archived-At: Subject: Re: [dmarc-ietf] Response to a claim in draft-crocker-dmarc-author-00 security considerations X-BeenThere: dmarc@ietf.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Domain-based Message Authentication, Reporting, and Compliance \(DMARC\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Jul 2020 00:52:50 -0000 This is a multi-part message in MIME format. --------------327D9A1A8416A8ACFBF3BE39 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit On 7/19/2020 5:04 PM, Murray S. Kucherawy wrote: > On Sun, Jul 19, 2020 at 11:33 AM Dave Crocker > wrote: > > The track record is that people are unreliable at this. > > There is quite a bit of distance between 'unreliable' and 'blindly > open and read absolutely everything'. > > Is there? Yes. > If there's no part of the From field that can be considered reliable, > then by opening even this email am I not exhibiting nearly-blind faith > that the indicators I can see (in this case the string "Dave Crocker > (gmail.com )") have not been falsely generated?  How > is this message, in terms of its trustworthiness, different from any > other? It's an act of curiosity, not faith.  You know that mail can be spoofed.  You might even suspect that I'm capable of lying. (Silly, I know, but...) Or that I might be wrong. (Truly a foolish thought.)  So the process of deciding on the validity and worth of my message is incremental and heuristic. Human evaluation processes vary, but mostly are pretty complex. Except when they aren't, though then it's often problematic. Mostly, your line of comments is trying to apply logical reasoning, which is rarely helpful in assessing human behavior. All of which is why this is a really terrible forum for making assertions or, worse, decisions, about end-user behavior. Whereas talking in terms of receiving filtering engines is both simpler and more useful. d/ -- Dave Crocker Brandenburg InternetWorking bbiw.net --------------327D9A1A8416A8ACFBF3BE39 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 8bit
On 7/19/2020 5:04 PM, Murray S. Kucherawy wrote:
On Sun, Jul 19, 2020 at 11:33 AM Dave Crocker <dcrocker@gmail.com> wrote:
The track record is that people are unreliable at this.

There is quite a bit of distance between 'unreliable' and 'blindly open and read absolutely everything'.

Is there?

Yes.


If there's no part of the From field that can be considered reliable, then by opening even this email am I not exhibiting nearly-blind faith that the indicators I can see (in this case the string "Dave Crocker (gmail.com)") have not been falsely generated?  How is this message, in terms of its trustworthiness, different from any other?

It's an act of curiosity, not faith.  You know that mail can be spoofed.  You might even suspect that I'm capable of lying. (Silly, I know, but...) Or that I might be wrong. (Truly a foolish thought.)  So the process of deciding on the validity and worth of my message is incremental and heuristic.

Human evaluation processes vary, but mostly are pretty complex.  Except when they aren't, though then it's often problematic.

Mostly, your line of comments is trying to apply logical reasoning, which is rarely helpful in assessing human behavior.

All of which is why this is a really terrible forum for making assertions or, worse, decisions, about end-user behavior.

Whereas talking in terms of receiving filtering engines is both simpler and more useful.

d/

-- 
Dave Crocker
Brandenburg InternetWorking
bbiw.net
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