On Friday, September 10, 2010 06:37:46 pm Steve Atkins wrote:
> On Sep 10, 2010, at 2:31 PM, Scott Kitterman wrote:
> > On Friday, September 10, 2010 03:17:47 pm Steve Atkins wrote:
> >> On Sep 10, 2010, at 11:27 AM, Charles Lindsey wrote:
> >>> On Fri, 03 Sep 2010 15:15:37 +0100, Hector Santos <[email protected]>
> > 
> > wrote:
> >>>> I think you need to better appreciate and understand how fundamental
> >>>> the "Message" From field for any forms of communications and/or mail
> >>>> networks is.  It would be a radical change to open up this door and
> >>>> "Pandora box" to make it the norm and mindset that a From: is
> >>>> unreliable. Not saying it is not prone to abusive, but fundamentally,
> >>>> when people believe in the message, they also make that natural
> >>>> trusted tie to the author of the message.
> >>> 
> >>> Yes, but nobody is trying to change that. We seem to be agreed that
> >>> what a mailing list sends is, from some POV, a "new" message, and so
> >>> logically a new "From:" is not wholly out of order.
> >> 
> >> What's the benefit to this, though, other than obscuring the original
> >> author?
> > 
> > If you agree with John Levine's proposal that mailing list mail is, in
> > general, not a problem then there is negative value in mailing lists
> > throwing away (discarding) good mail from domains that happen to use
> > ADSP Discardable (or any other mechanism for inferring something from
> > the lack of a signature - this isn't really ADSP specific, it's just the
> > implementation we have at the moment).  If this negative event can be
> > avoided by the simple mechanism of using a mailing list specific
> > "Message" From, then that is a benefit.
> 
> Rather than go into the general reasons why I think this is not
> something that ADSP users really want, I'll give a concrete
> example.
> 
> Lets say this mailing list rewrites the From: address in some
> reasonably mechanical manner, and the From: field of
> this message were rewritten as (making up syntax on
> the fly)...
> 
> From: steve%blighty.com%[email protected]
> 
> ... such that recipients (or their MUAs) know that this mail
> was sent by [email protected] via a mailing list at
> dkim.org.
> 
> There's nothing to stop me from sending mail
> From: billing%paypal.com%[email protected], as
> the mailing list isn't using ADSP. And there's certainly
> nothing to prevent me from sending mail from
> billing%paypal.com%[email protected] that has
> a valid first-person signature.
> 
> That means that, as far as the end user is concerned,
> I can send them email that is "from" [email protected],
> even though paypal.com is using ADSP to ask receivers
> to discard mail that claims to be from paypal.com but
> is not validly signed by paypal.com.
> 
> Given the whole point of ADSP is "Discard if you're not
> sure", I don't think that's what an ADSP using domain
> would want.
> 
> (The effect is softened somewhat if you use random
> from addresses with no connection to the real address,
> but only somewhat. And that damages the communication
> between users quite a bit more. That's what I meant when
> I talked about obscuring the author, upthread).
> 
> >  This is
> > 
> > not the only potential use of such a feature.  I've spoken to one MLM
> > developer who told me the feature has been previously requested for
> > privacy reasons nothing to do with DKIM or ADSP.
> 
> That would be "for obscuring the original author", and
> it's certainly possible for MLMs to do that now, though few
> do.
> 
> > I think this is quite reasonable as it would inoculate MLM users from
> > ADSP (or similar) problems in a way that does not limit their ability to
> > promote communication among their subscribers (which is what mailing
> > lists do).
> 
> I don't think it inoculates them against ADSP problems - rather
> it opens them up to violations of the security model that ADSP
> would like to impose.
> 
This is only true if John is wrong and mailing lists are a vector that we need 
to worry about.  I happen to generally agree with him on this.

Scott K
_______________________________________________
NOTE WELL: This list operates according to 
http://mipassoc.org/dkim/ietf-list-rules.html

Reply via email to