[turbojet1321]

There is myID (formerly myGovID) which would be the logical vehicle for a government provided age verification service. I've heard (but can't find a source) that it's build on OIDC/OAuth, so extending it to be an IdP exposing only specific claims (ie, age) shouldn't be a huge leap.

[linuxandrew]

myID as it stands is a bit of a farce. It uses OIDC under the hood, but it only supports end users that download the myID app on their smartphone via the Google Play Store or Apple App Store. Security is effectively outsourced to Google and Apple as the user's identity is "pinned" to their smartphone.

Take myGov in contrast which is web-capable and supports users to use a Yubikey or Passkey/Webauthn-capable device to authenticate.

Under the Australian Digital ID scheme myGov will likely be usurped by myID, which is, in my view, an inferior scheme which blatantly ignores basic standards.