Per the recent discussion regarding tor and wikipedia, I've hacked together an implementation of the basic system from Chaum, Fiat and Naor's 1990 "Untraceable Electronic Cash" paper. This system allows CAs to blindly issue tokens (or "coins") which can then be "spent" elsewhere. It runs in perl, and comprises a CA, nym-maker, client application and auth checker (for the server). The tarball is here: http://www.lunkwill.org/src/nym/ Of course, it's useless at the moment since it gives out tokens indiscriminately (and probably has massive bugs), but if anyone actually cares about this idea, it will be (more or less) easy to do the following: * Put up a sample CA and server that people can use (potentially as hidden services). * Make the CA issue only one token per email address, or one token per IP address, one per computational puzzle, one for every $20 mailed in... * Automatically expire CA keys and generate new ones on a regular basis (rather than bothering with CRLs) * Instead of randomly generated tokens, have the CA sign an actual X.509 cert request, which will then become a perfectly valid X.509 cert useful as a client-side cert in unmodified browsers and web servers * Create some sort of aid for maintaining server-side (or CA) blacklists of improperly behaving users * Check to see if the protocol is actually still secure and properly implemented. Comments welcome. -J ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.leitl.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE [demime 1.01d removed an attachment of type application/pgp-signature which had a name of signature.asc]