It doesn't look like this would even work for the offline stuff that PGP targets. The session key seems to be linked to the public key. So really only good for

It doesn't look like this would even work for the offline stuff that PGP targets. The session key seems to be linked to the public key. So really only good for things where you throw away the keys after the session has closed. Forward secret TLS for example. Unless I am missing something, the reference to OpenPGP and S/MIME is gratuitous.