On Wed, 24 Aug 2005, Douglas Otis wrote: > > > I don't see where that talks about using the revocation ID to detect > > forgery. > > The recent suggestion was to consider the binding of the > mailbox-address/ signing-domain/revocation-identifier by the MUA as an > opportunistic identification, rather than attempting less protective > domain-wide assertions by the SSP. The MUA is able to associate visual > items from prior correspondents and obtain a higher granularity and > history of signed message sources without using any DNS lookups.
That seems plausible, but it assumes that the revocation ID will be varied per sender and I don't think this will always be the case. For example: attack: Mr Vendetta signs up for marketing email from example.com, then spams it widely in order to damage the company's reputation. (This is a direct reputation attack, as opposed to the parasytic reputation attack we have considered so far.) defence: Example.com wants to revoke email sent to Mr Vendetta without affecting their other customers. Therefore they use a revocation ID per recipient. This doesn't break your scheme, but it does make it look a bit shaky. Tony. -- f.a.n.finch <[EMAIL PROTECTED]> http://dotat.at/ BISCAY: WEST 5 OR 6 BECOMING VARIABLE 3 OR 4. SHOWERS AT FIRST. MODERATE OR GOOD. _______________________________________________ ietf-dkim mailing list http://dkim.org
