ietf-dkim
[Top] [All Lists]

Re: [ietf-dkim] Re: Attempted summary

2006-01-24 12:07:06

On Jan 24, 2006, at 10:23 AM, Jim Fenton wrote:

Hector Santos wrote:

I suggest we try to keep away introducing a reputation system into the algorithm. It can always be added separately and independently. But as a protocol, I don't think it will be widely accepted for a few simple reasons - What Reputation System? Whose Reputation System? What is the "Fancy System?" Will it become a 3rd party central repository? Will there be a buy-in fee? Republican vs. Democrats?, etc. It is going to very hard to justify further support when we now have to begin promoting 3rd party A/R into our product lines.

I wasn't trying to introduce a reputation system into the algorithm. I'm not even sure whether reputation or accreditation will prevail when we get to that at some point in the future. The questions you raise are exactly why we don't want to go down that rathole.

There is a banal reality that needs to be accepted however. Bad actors are capable of implementing a valid DKIM signature. Bad actors are capable of obtaining an account within a large domain, whether through compromised systems, wireless-access points, free email-address accounts, subscriptions to list-servers, etc. This also means the signature itself is prone to replay abuse. There is a significant challenge ahead dealing with these issues without being blind to reasonable solutions. While a community list offers less administrative effort, the same approach may apply to private efforts made the administrator. There are solutions, but yes they will likely involve some type of reputation being applied. There are companies willing to offer something like a DKIM-Adopters-List as a free service. Creating a list should not be seen as a difficult obstacle.

DKIM does offer value beyond providing an identifier that is closer to the source of a possible problem. DKIM can allow the recipient to recognize the source of their correspondences and know when a source changes. This does not require the application of any type of reputation and may well depend upon out-of-band information found within the message as a method to safely identify the source.

Any expectation that SSP offers value is based upon the expectation that the recipient can visually recognize the sender by what is seen with the MUA. There are many reasons to doubt that this is either safe or sensible.

-Doug

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