This seems to be what "double-blind" verification is doing:
> The report highlights emerging approaches, such as “double-blind” verification systems used in France, where websites receive only confirmation that a user meets age requirements without learning the user's identity, while the verification provider does not see which websites the user visits.
> The report highlights emerging approaches, such as “double-blind” verification systems used in France, where websites receive only confirmation that a user meets age requirements without learning the user's identity, while the verification provider does not see which websites the user visits.