Re: [Asrg] misconception in SPF

"John Levine" <johnl@taugh.com> Sun, 09 December 2012 19:16 UTC

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Date: Sun, 09 Dec 2012 19:16:14 -0000
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From: John Levine <johnl@taugh.com>
To: asrg@irtf.org
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Subject: Re: [Asrg] misconception in SPF
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>> a forged email pass anyway

No antiforgery scheme can defend against fakes that only sort of match
the forgery target.  We call this the paypai problem.  The only
approach I can see that has any hope of success is to figure out some
way to mark real mail from a category of targets (banks, say) in a way
that bad guys can't fake.  

But this is specific to each target group.  The fact that mail from me
doesn't have a seal saying that it's from a bank doesn't mean that
it's forged or otherwise bad.


>> I think is a misunderstanding of a huge part of the operators
>
>Is it? Have you evidence, even if it is only anecdotal, that such a misunderstanding exists?

I'm with Martijn.  Other than the test message you sent the other day,
I don't think I have ever seen a phish that used a subdomain of the
target.  Ever.