I wrote :
Poster crypts 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]
At 09:24 PM 3/4/96 -0800, Alan Bostick replied:
Is this the right way to go about doing this?
If the mailing list has N members, then, for each message posted to the list, the list processor must decrypt the message and then reencrypt it N times.
Hmm thats not what I meant - I just envisioned giving all the recipient public keys to pgp and saying letting it do the rest. This does result in all recipients gettingthe key fingerprints of all other recipients which is not a problem in my application. Alan goes on to suggest sumthing very similar except that he does not decrypt the body first - which apart from meaning I'd have to hack pgp acheives the same effect. The overal intent was to have a message go from one list member to all others with a) a signature to provide strong attribution and a measure of non repudiation b) low probability of interception c) only the gateway has to have all the public keys. Inbound the process looks like this: decrypt and validate signature (leaving original signature) add gateway info (sender signature validation, date received etc) sign the whole thing with the gateway key. crypt with all list member keys (i.e. one message readable by any member) send to members. Several people have pointed me at PGPdomo which I now have a copy of and will be looking at as a basic for this (assuming it's not an exact fit already).\ [thanks to all those who responded] John -- John Pettitt email: jpettitt@well.sf.ca.us (home) jpp@software.net (work)