> -----Original Message----- > From: ietf-dkim-boun...@mipassoc.org [mailto:ietf-dkim-boun...@mipassoc.org] > On Behalf Of MH Michael Hammer (5304) > Sent: Friday, October 15, 2010 1:52 PM > To: Bill Oxley @ Cox; dcroc...@bbiw.net > Cc: ietf-dkim@mipassoc.org > Subject: Re: [ietf-dkim] detecting header mutations after signing > > And this is where I angst. In all the discussions of a broken signature > being morally equivalent to unsigned, the thrust has been that it was > likely broken in transit. We failed to have the discussion of it being > intentionally broken in transit as an attempt to game the system. For > header mutations after signing (which are likely to be a malicious > attempt in the specific cases we have been discussing) I feel that > treating it as simply the same as unsigned is ignoring the potential > maliciousness.
I think the problem is it's hard to tell using an algorithm. A human can perhaps look at a modification and qualify it as an operational side-effect or something deliberate intending to deceive, but it's pretty hard to codify that kind of logic, especially without some foreknowledge about what downstream agents are going to do with the message (which would make such an algorithm heinously big). > I recognize what Murray and Dave have said on this point but it grates. I think it's an unfortunate reality as well; absent a way to tell the difference, it seems the best option is to act like there isn't any difference. Interestingly, I think the same logic applies to domain reputation: It's easy to shed a bad reputation by changing domains, so in the end I expect a bad reputation will be the same as no reputation. -MSK _______________________________________________ NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html
