Subject: RE: How is SPF different from RMX?

From: "Hallam-Baker, Phillip" <[email-masked]>
Date: Wed, 4 Aug 2004 08:47:22 -0700

> On Mon, 2 Aug 2004, Hallam-Baker, Phillip wrote:
> >
> > I have asked repeatedly for a specific fault in Sender-ID. 
> The only response
> > that has been given is a repeat of the vague claim that the 
> protocol is
> > flawed and cannot work.
> 
> http://www.imc.org/ietf-mxcomp/mail-archive/msg02817.html
> http://www.imc.org/ietf-mxcomp/mail-archive/msg02818.html

More proof by non-existent reference.

These are pointers to issues that have already been raised, are not
considered critical and in any case fall far short of the claims
made by Dean of Death of the Internet: News at 11.

Sure this form of authentication is not going to work for everyone.
Nobody has ever claimed complete coverage. For those Sender-ID serves
it is cheap and efficient.

Claims that a system will not work are of a very different order to
claims that the system will bring down the Internet.

---

From: Tony Finch <[email-masked]>
Date: Wed, 4 Aug 2004 17:20:45 +0100

> made by Dean of Death of the Internet: News at 11.

Not critical?! I'm expecting deployment of SPF and Sender-ID to cause
significant problems for my site, and I neither publish nor check these
DNS records. A protocol that causes problems for sites that do not
participate is seriously flawed.

Many of the work-arounds for the problems caused by designated sender
protocols weaken the protocols themselves (e.g. trusted-forwarder.org or
inserting a Resent-From: [email-masked] header before every
Received: header) or weaken other existing security mechanisms (e.g. SRS
and open relays).

Of course the fundamental reason for the flaw is obvious: a trivial
failure to apply the end-to-end principle.

Tony.
-- 
f.a.n.finch  <[email-masked]>  http://dotat.at/
BERWICK ON TWEED TO WHITBY: WEST OR SOUTHWEST 2 OR 3 INCREASING 3 OR 4. FAIR.
GOOD. SLIGHT OR SMOOTH.