Further, S/MIME's signed
+ encrypted message format reveals the identity of the signatory. My
argument is simply that the relative quality is still controversial.
S/MIME reveals the name in the certificate. Under issuing
policy this may or may not refer to an identity of a real
world object.
S/MIME key distribution design faciliates users knowing
whether the name is likely to be real or a mere personae.
The task of picking a winner is best left to the market.
S/MIME can be operated in PGP mode, and I expect to see
this emerge shortly.