Jonathan Wienke <JonWienk(_at_)ix(_dot_)netcom(_dot_)com> writes:
As long as only old-style RSA keys are used when encrypting a message 5.x
will talk to 2.6.x. If you create an RSA key with a CMRK packet or other
5.x features, it is not hard to understand why 2.6.x would break.
Just a nit: I don't think pgp5.x will let you put a CMR (aka packet no
666) signature subpacket on an RSA key. (At least it was described
that PGP 5.x for business had RSA keys disabled for this reason).
This breaks orthogonality, not that I'm complaining in this case, for
obvious reasons. Also it may be that this is an implementation choice
rather than a restriction of the standard.
Adam