I don't see how authorization certificates solve this problem. How would you determine if someone was qualified to receive an authorization certificate? And what would you do to make them stop using the service if they abuse it, and to stop them from getting new authorization certificates?

Thanks, Hal

I guess I was mistaken about how rigorous identification checking was performed at various CAs. Verisign used to advertise three levels of CA checking, although I can only find two on their Web site at this time. The lowest, Class 1, is simply tied to your email address and is inadequate for my purposes. Class 2 Digital IDs provide identity assurance by requiring third-party confirmation of your name, mailing address, and other personal information. Although by no means bullet-proof dependence on Class 2 might be a workable alternative to a substantial, up-front, money escrow (as suggested) which I believe would make my service unworkable. -- Steve