Earlier quoted context omitted.
The article talks about the possibilities of malicious cloning of these tokens by third parties, but fails to identify the much more common use case, and one that makes this scheme useless for age verification. It's one thing to be concerned about someone stealing my credential, but another to prevent the transfer of these credentials, especially if they are limited use credentials. The entire point of age verificati…
Yes, this is the part of the issue that is so frequently ignored: Anonymous age verification schemes are easily defeated through proxying because there wouldn't be any consequences for selling your tokens. "Install this app on your phone and we'll pay you $1 per day" and it will mint your anonymous identity tokens and send them off to kids who want to buy them. If there's no way to track the tokens, there is no possi…
Not if you use a challenge-response protocol where the client returns a zero-knowledge proof of age, where the proof incorporates a random string sent by the website.
The traceable stuff is private information that the website never sees. If a minor is caught with it, then law enforcement has local access to the minor's hardware and can probably view the private data.
At that point, the private key can be put on a public revocation list. The zero-knowledge proof can include a proof that you're not on the revocation list. Once you've been revoked, you have to go through the hassle of setting this all up again, which might be enough incentive to keep it reasonably secure.