From: Blanc Weber <blancw@microsoft.com>

I'm sure I don't understand, said Alice in Wonderland: cryptology is to create anonymity sufficient to prevent the identification of a person; however, it is desireable to have a method/means of verifying identity such that in games or digicash or whatnot, someone cannot take advantage of that ability to obfuscate precise references to themselves.

How could these two opposing needs be simultaneously satisfied? It sounds like a self-defeating proposition.

Blanc

You don't try to satisfy these simultaneously. Rather, one or the other goal is achieved by the participants voluntarily participating in a protocol. In some contexts, absolute anonymity is desired and achieved. In others, the participants agree to some restrictions on their anonymity in order to allow various kinds of agreements. I may not be willing to loan you money if you are totally anonymous; on the other hand, I might be able to loan it to you if your anonymity would be broken only if you didn't pay it back, for example. If you didn't want to take the chance on breaking your anony- mity, you wouldn't have to. You would just choose not to play my game. The point of a lot of this work with pseudonyms and credentials and such is to create a lot of different possible options along the scale between perfect anonymity and perfect identification. That way people will be able to trade off their various requirements and come as close as possible to their ideal position. Hal