Re: [dmarc-ietf] Response to a claim in draft-crocker-dmarc-author-00 security considerations
Dave Crocker <dhc@dcrocker.net> Sun, 26 July 2020 11:33 UTC
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To: Alessandro Vesely <vesely@tana.it>, dmarc@ietf.org
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From: Dave Crocker <dhc@dcrocker.net>
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Organization: Brandenburg InternetWorking
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Date: Sun, 26 Jul 2020 04:32:59 -0700
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Subject: Re: [dmarc-ietf] Response to a claim in draft-crocker-dmarc-author-00 security considerations
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On 7/20/2020 1:44 AM, Alessandro Vesely wrote: > On Sun 19/Jul/2020 20:33:46 +0200 Dave Crocker wrote: >> The essential point that needs to be made is that standards like this >> MUST NOT be cast in terms of what end users will do. In practical >> terms, this work has nothing to do with end users. Really. Nothing. >> [...] >> (*) I've seen one posting here or somewhere else that noted that >> letting bad mail through can lead to end-users being deceived. I'll >> claim that while true, it is not relevant, since the behavior happens >> after DMARC, and the like, are relevant. That is, DMARC, etc., do >> not inform the end-user behavior. > > Aren't those two paragraphs self-contradictory? No. A specification defines a field of activity. (A sandbox.) Things outside that field are not relevant to the specification, even though they might be highly relevant from a larger perspective. There is a constant desire to have a specification that involves security-related decision-making include the (human) recipient be an actor within the scope of the specification. The first paragraph, quoted above, is a reminder that we need to resist that desire. The second paragraph, quoted above, is a reminder about a specific example of this, namely about the DMARC specification. It acknowledges that, in general, recipients can be deceived, for the specific From: field protection that DMARC provides, the recipient is not a relevant actor. > If DMARC were dependable, maybe users would learn to trust From:. Or > maybe not. Avoiding end user considerations cuts both ways. Yet, we > can trust that if we do a well-defined, clear job, then the whole > system will work better. It is expensive and highly risky to create an international standard that relies on such a tenuous hope about future behavior, especially in the face of consistent empirical evidence that it won't happen. d/ -- Dave Crocker Brandenburg InternetWorking bbiw.net
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- [dmarc-ietf] Response to a claim in draft-crocker… Kurt Andersen (IETF)
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker on behalf of Kurt Andersen
- Re: [dmarc-ietf] Response to a claim in draft-cro… Douglas E. Foster
- Re: [dmarc-ietf] Response to a claim in draft-cro… Alessandro Vesely
- Re: [dmarc-ietf] Response to a claim in draft-cro… Jim Fenton
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Murray S. Kucherawy
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Murray S. Kucherawy
- Re: [dmarc-ietf] Response to a claim in draft-cro… Alessandro Vesely
- Re: [dmarc-ietf] Response to a claim in draft-cro… Douglas E. Foster
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… John Levine
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] no from addresses nowhere, Respo… John Levine
- Re: [dmarc-ietf] Response to a claim in draft-cro… Murray S. Kucherawy
- Re: [dmarc-ietf] Response to a claim in draft-cro… Murray S. Kucherawy
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Murray S. Kucherawy
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Douglas E. Foster
- Re: [dmarc-ietf] Response to a claim in draft-cro… Alessandro Vesely
- Re: [dmarc-ietf] Response to a claim in draft-cro… Laura Atkins
- Re: [dmarc-ietf] Response to a claim in draft-cro… Benny Lyne Amorsen
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dotzero
- Re: [dmarc-ietf] Response to a claim in draft-cro… Benny Lyne Amorsen
- Re: [dmarc-ietf] Response to a claim in draft-cro… Douglas E. Foster
- Re: [dmarc-ietf] Response to a claim in draft-cro… Jesse Thompson
- Re: [dmarc-ietf] Response to a claim in draft-cro… Brandon Long
- Re: [dmarc-ietf] Response to a claim in draft-cro… Brandon Long
- Re: [dmarc-ietf] Response to a claim in draft-cro… Brandon Long
- Re: [dmarc-ietf] Response to a claim in draft-cro… Murray S. Kucherawy
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… John Levine
- Re: [dmarc-ietf] Response to a claim in draft-cro… Laura Atkins
- Re: [dmarc-ietf] Response to a claim in draft-cro… Laura Atkins
- Re: [dmarc-ietf] Response to a claim in draft-cro… Laura Atkins
- Re: [dmarc-ietf] Why are MUAs hiding or removing … Douglas E. Foster
- Re: [dmarc-ietf] Response to a claim in draft-cro… Jesse Thompson
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Why are MUAs hiding or removing … Brandon Long
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dotzero
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Hector Santos
- Re: [dmarc-ietf] Why are MUAs hiding or removing … Joseph Brennan
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dotzero
- Re: [dmarc-ietf] Response to a claim in draft-cro… Joseph Brennan
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Brandon Long
- Re: [dmarc-ietf] Response to a claim in draft-cro… Douglas E. Foster
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Why are MUAs hiding or removing … Jesse Thompson
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Doug Foster
- Re: [dmarc-ietf] Response to a claim in draft-cro… John Levine
- Re: [dmarc-ietf] Response to a claim in draft-cro… Jesse Thompson
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dotzero
- [dmarc-ietf] DMARC marketing Jim Fenton
- Re: [dmarc-ietf] Response to a claim in draft-cro… Joseph Brennan
- Re: [dmarc-ietf] Why are MUAs hiding or removing … Joseph Brennan
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Why are MUAs hiding or removing … Benny Pedersen
- Re: [dmarc-ietf] Why are MUAs hiding or removing … Joseph Brennan
- Re: [dmarc-ietf] Why are MUAs hiding or removing … Benny Pedersen
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Hector Santos
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Jim Fenton
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Douglas E. Foster
- Re: [dmarc-ietf] Response to a claim in draft-cro… Hector Santos
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker
- Re: [dmarc-ietf] Response to a claim in draft-cro… Hector Santos
- Re: [dmarc-ietf] Response to a claim in draft-cro… Douglas E. Foster
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dotzero
- Re: [dmarc-ietf] DMARC marketing Jesse Thompson
- Re: [dmarc-ietf] Response to a claim in draft-cro… Jesse Thompson
- Re: [dmarc-ietf] Response to a claim in draft-cro… Dave Crocker