[Cryptography] Anonymous age verification

[John Levine]

It appears that zeb--- via cryptography <zeb at qtt.se> said:
>The EU has implemented an anonymous age verification app (in minutes, using Claude, I'm led to believe).
>The current implementation can be bypassed (even en masse using a browser add-on).
>Disregarding motives and current implementations: is anonymous age verification possible, even in principle?

I think it depends what you mean by anonymous.

I have heard of designs where something in the phone determines your age
somehow, take a picture of an ID, estimate from a selfie, whatever. Then there's
an API which answers yes or no to "is the phone user older than X?" as part of
an app installation, or perhaps the app package has a minimum age and the phone
won't even install apps for which you're too young, so in principle the app need
not know anything about you.

You don't have to tell us all the reasons that's not likely to be as anonymous
as you'd like.

R's,
John