Looking for code to run an encrypted mailing list

I'd like to run an encrypted mailing list - the model I'm linking of is this .. Poster cryptes mail with pgp using list exploder key. List exploder decrypts mail and recrypts with keys for all current list members and then sends the mail. [I don't want all the list members to need to know every other list members public key] Before I lanch into hacking majordomo - has anybody done this already or somthing like it ? John -- John Pettitt email: jpettitt@well.sf.ca.us (home) jpp@software.net (work)