secure listservs?

[craig@passport.ca (Craig Hubley)]

Looking for some secure listserv software, preferably something
that will automatically generate purpose-specific PGP keys for
each user and one for the listserv.  Each user encodes mail for
the list with the list's public key, signing it with their own
private key (either the purpose specific one, or their regular
key).  Each user receives mail from the listserv encoded with
the corresponding public key.  That way each user has a choice
of using their published key (for convenience) or their purpose-
specific key, possibly in conjunction with an anonymous remailer,
to ensure the segmentation of these communications from others
that they may engage in.

Anyone seen/built anything like this ?
-- 
Craig Hubley                Business that runs on knowledge
Craig Hubley & Associates   needs software that runs on the net
mailto:craig@hubley.com     416-778-6136    416-778-1965 FAX
Seventy Eaton Avenue, Toronto, Ontario, Canada M4J 2Z5