>No identifier is going to be free as in speech - that would defeat the purpose. I would say that a public key would work well as a free as in speech identifie

>No identifier is going to be free as in speech - that would defeat the purpose. I would say that a public key would work well as a free as in speech identifier. It uniquely identifies an address-holder, and the full software necessary to send messages using that key can be obtained and held on one's own. The problem comes when expecting an identifier to be associated with a person, since there you need a trusted authority to relate between names and keys.