ietf-dkim
[Top] [All Lists]

Re: [ietf-dkim] draft-fenton-dkim-threats-00

2005-10-05 14:38:55
Douglas Otis wrote:


On Oct 5, 2005, at 9:57 AM, Hallam-Baker, Phillip wrote:

I read the threat analysis and agree with the content

I think that we can elaborate the threats against DKIM indefinitely. The important thing is that the threat analysis in its current form answers the two major questions relevant at this point:

* What threat does DKIM defend against

* Given the previous attempts to do this type of work why is DKIM likely to be more successful?


I agree, there should be greater clarity with regard to realistic defenses offered by the DKIM mechanism, especially in the third-party scenario you described.

Do you really agree? I read Phill's comment as "we could go on forever, but this is pretty good now" while I read yours as "needs improvement".


...

What DKIM does is to allow a party to accept responsibility for an email message. This is very different to the traditional S/MIME, PGP, PEM, MOSS objectives.

...

Repudiation offers _minimal_ value when combined with an easy to exploit mailbox-domain authorization scheme. Abusers will adopt requisite conventions that defeat repudiation. Ascribing repudiation as a goal would be a mistake when reputation _must_ be applied as a defense. However, with minor modification permitting replay abatement, reputation should offer protection.

On good advice, I steered clear of the topic of repudiation. Is there someplace the document implies repudiation protection?

-Jim
_______________________________________________
ietf-dkim mailing list
http://dkim.org