[petu]

https://github.com/eu-digital-identity-wallet/av-doc-technic...

> Since Proof of Age Attestations are designed for single use, the system must support the issuance of attestations in batches. It is recommended that each batch consist of thirty (30) attestations.

It sounds like application would request batch of time-limited proofs from government server. Proofs gets burned after single use. Whether or not you've used any, app just requests another batch at a set interval (e.g. 30 once a month). So you're rate limited on the backend.

Edit: seems like issuing proofs is not limited to the government, e.g. banks you're client of also can supply you with proofs? (if they want to partake for some reason). I guess that would multiply numbers of proof available to you.

[voxic11]

Ok I have been convinced this is a technically feasible solution that could preserve privacy while reasonably limiting misuse. That said I'm worried that the document you linked does not require relying parties implement the zero knowledge proof approach. It only requires that they implement the attestation bearer token approach which is much weaker and allows the government to unmask an account by simply asking the relying party which attestation token was submitted to verify the account.

> Relying Party SHALL implement the protocols specified in Annex A for Proof of Age attestation presentation.

> A Relying Party SHOULD implement the Zero-Knowledge Proof verification mechanism specified in Annex A