Yes, I understand, but you mix up identity with proof of identity. My non-web identity is my name. But me saying that my name is John Doe is not a proof that t

Yes, I understand, but you mix up identity with proof of identity. My non-web identity is my name. But me saying that my name is John Doe is not a proof that this is my name. In the same way, me saying that I have identification number 12345678 isn't proof that I actually have that number. As I wrote, I have a government issued identification number. This number can be looked up by any citizen in the country since it's public info. You can even look it up online - it's not secret. But someone knowing the number doesn't mean they can prove it is their number, because proof of identity is not in the number itself - for that we use public/private keys and other secure mechanisms. I understand that this is not how it works in the US because some organization treats the SSN as secret. But that's not an issue with government issued identity number as a form of identity, it's an issue with the US system. Other countries does not have the same issue, since they didn't mix up identity with proof of identity.