Pseudonymity for tor: nym-0.1

[Jason Holt <jason@xxxxxxxxxxxx>]

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