(The following message arrive in my mailbox, with a request to repost it anonymously. Sometimes these "manual" methods work pretty well! --Tim May) Tim, I have been following your arguments in CypherPunks. The name will turn off a lot of your natural friends, but your arguments are dead on. The Crux of the matter is digital cash. And getting these anonymous remailers working. PGP is a basic enabling thing. Not that RSA hasn't been around forever, but it just wasn't useable without a standard. My deepest gratitude to you and your friends. The remailer business needs to get standardized also. My personal hack is attached below. One problem not addressed in the first crop of remailers is the problem of how do you handle return paths. There are lots of trivial ways to get anonymous outgoing mail. Most telephone systems do not identify the caller, there are lots of other ways to get this function. But the problem is getting an answer back with out unmasking. The mathematicians may be able to conjure up a better scheme, but I see the backward security to be simply a matter of tearing the connection (return path down) faster than it can be backtraced. It would be nicer if some kind of DC-net return path could be devised. But timeout control will definitely work. With a large number of the forwaring nodes, and multi-hop paths, it would become quickly very impractical to shake down the originator, So the return path could be left "up" for quite some time before having to replace it. Certainly long enough for a reasonable reply. Better yet of cource would be a completely uncrackable return path that you could leave up long enough to use institutional advertising. Eg: run a business from. Another way to leave up long lasting connections (return paths) is to select one really HARD point node. This is the one they have to shake down first. And use continuously shifting paths behind that node. (all sounds like a router ? ) If you could repost this anonymously I sure would appreciate it. I am (ahem, respectable), and have some kids left to feed. Could you tell me how to find out more about David Chaum's work? do you have an email address for him, is he on one of the mailers, or have anything published? My hunch is that this whole business could heat up fast. Within just a few years the government could be forced into "wage/price" controls. A great application for the NREN? Thanks, xxxxxxxx@yyyyyy.zzz ---------Tear off ----- This is a proposal for a simple anonymous forwarding protocol. 1> With the exception of cases 4> and 5> below: Any message addressed to the forwarding node that does not contain a valid PGP encrypted block, encrypted with the node's public key causes the forwarding node to reply to the sender with its public key, plus whatever other text the node wishes to add. 2> If a properly encrypted message is decrypted with the node's secret key; The body of the decrypted message is scanned for the following sequence: "Please forward this message to:" FORWARD.ADDRESS "Thank you." The trigger strings are what is shown above in the quote marks but not including the quote marks. No actual quote marks are used. Everything after the period of the Thank you. string is forwarded to the address specified by the FORWARD.ADDRESS string. Messages not containing the forwarding request are presumed to be addressed to the node itself. 3> The incoming RETURN.ADDRESS and the FORWARD.ADDRESS are stored by the node. ---- Clean up. 4> Receipt of a message whose RETURN.ADDRESS matches a stored FORWARD.ADDRESS will be repeated without modification to the stored RETURN.ADDRESS associated with the stored FORWARD. ADDRESS. Bounced mail is returned similarly, 5> Receipt of a message whose RETURN.ADDRESS matches a previously stored RETURN.ADDRESS will cause a message to be forwarded to the previously stored FORWARD.ADDRESS If the incomming message in this case contains a valid encrypted block, It will be decrypted and forwarded. Otherwise, whatever contents of the body found will be forwarded. Subject lines should be repeated without modification. Null bodies or subject lines should work. 6> In both cases 4> and 5>, the stored RETURN/FORWARD addresses are erased. -xxxxxxx -- .......................................................................... Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay@netcom.com | anonymous networks, digital pseudonyms, zero 408-688-5409 | knowledge, reputations, information markets, W.A.S.T.E.: Aptos, CA | black markets, collapse of governments. Higher Power: 2^756839 | PGP Public Key: by arrangement.