[ietf-dkim] Data integrity claims

[Dave CROCKER]

On 10/15/2010 8:32 PM, Mark Delany wrote:
> Therefore one could
> argue that DKIM is "protecting" that relationship between the message
> and identifier.

Clever phrasing.  Might be too subtle for general use, but I think it offers a 
perspective that could be useful.

I think the issue here is that when people talk about protecting a message, they 
tend to have in mind all sorts of attacks designed to trick users.  DKIM 
actually does not have much to say about such things.

Yes, it ties an identifier to a bag of bits, and yes it specifies what those 
bits are, but it really does deal only with those bits and not (necessarily) the 
entire message.  And its protection of those bits is quite limited, relative to 
various important assertions that might be made about those bits (and/or the 
entire message) but which DKIM does not know or care about.

d/
-- 

   Dave Crocker
   Brandenburg InternetWorking
   bbiw.net