I would suggest that this might be better handled at a MIME level and
would thus not be restricted to S/MIME but MIME in general and would be
outside the scope of this list.
E.g. a MIME type application/super-compression means "decompress using
the super-compression algorithm and treat the result as a MIME entity".
There is no guarantee that the recipient supports this but then again
the recipient can't specify what MIME types they can view either. Maybe
we should have a "supported MIME types" authenticated attribute, or then
again maybe not.
Steve.
--
Dr Stephen N. Henson.
UK based freelance Cryptographic Consultant. For info see homepage.
Homepage: http://www.drh-consultancy.demon.co.uk/
Email: shenson(_at_)bigfoot(_dot_)com
PGP key: via homepage.