Age verification

[lists at notatla.org.uk]

Graham Cobb <g+ukcrypto cobb.uk.net>

>  2. Bank verifies your age.

>  3. You request them to sign a certificate stating that you are over a
>  specific age (say 18).

>  4. Bank provides the certificate to you.

>  5. You pass the certificate to the entity needing the proof (say, a
>  nightclub).

>  6. Nightclub validates the certificate against the bank's public key
>  (without needing to contact the bank).

>  The hard part would seem to be proving that the certificate relates to
>  the actual person who is presenting it (to a practical level of
>  certainty similar to traditional techniques), without allowing the
>  nightclub to find out who that person is! I assume it would have to be

https://en.wikipedia.org/wiki/Stefan_Brands
http://www.credentica.com/unique_features.html