When not doing privacy oriented cryptocurrency (cough money laundering cough) with ZKP's, if you really want private verification you are in a position where a single actor can authenticate the entire world and no one will know it happened. And to prevent it you assemble the pieces necessary to deanonymize anyone.
Make no mistake. ZKP age verification, as proposed, will just require multiple parties to collude to figure out your identity.
They can't even implement ZKP for remote attestation due to the auth-the-world problem.
If you read the link, that’s not necessarily how things have to work. You can make limited-use ZK schemes, plus you fall into the usual trap of binary thinking, that if something isn’t 100% effective it is necessarily 0%.
With ZKP age verification, services will not be able to track you without help from the CA. The CA will not be able to track you without help from the services. Both will contain the necessary information in their databases that when combined deanonymize you. The CA is the central authority/certificate authority.
So you should assume the government can track you, because you should assume both will be streaming those identifiers to it.
That's not really possible to explain in this space, unfortunately, but the overall idea is that there are mathematical techniques that allow you to prove that you have a valid certificate without revealing which one it is.
That would be ideal. However, this is tech proposal which takes so much of the slop out of the entire thing. With this implementation, there is no profit in it, unless your government is directly cooperating, aka a scandal in many countries.
When not doing privacy oriented cryptocurrency (cough money laundering cough) with ZKP's, if you really want private verification you are in a position where a single actor can authenticate the entire world and no one will know it happened. And to prevent it you assemble the pieces necessary to deanonymize anyone.
Make no mistake. ZKP age verification, as proposed, will just require multiple parties to collude to figure out your identity.
They can't even implement ZKP for remote attestation due to the auth-the-world problem.