To be clear, I’m not advocating for online age verification. I’m very much against it in any form. I’m just curious from a technical standpoint if it’s possible somehow to construct an accurate age verification system that doesn’t compromise a user’s privacy? i.e., it doesn’t expose the person’s identity to anyone nor leaves behind a paper trail that can be traced to that person?


That still creates a chain that can be followed. If the site you’re trying to enter is ever compromised, there will be record of your government code and whatever tracking is used to verify that you have entered your code.
I would be happy if the government was not involved in my online activities at all but I guess that ship is about to sail.
See also: timing attacks