By some stroke of luck, the NZ government recently put into place a robust privacy-preserving framework for digital identity [1].
They just launched the GOVT.NZ [2] app, and it contains a wallet that can store digital credentials. It's built by a local company called MATTR [3], who specialise in trust technology and exotic cryptography like zero-knowledge proofs. The first credential available this year will be a mobile drivers license, and we'll then be able to prove things about ourselves like whether or not we're over 18 (according to an accredited institution), completely privately over the internet and without sharing any other information.
I'm cautiously optimistic about the direction our digital ecosystem is heading in NZ :')
[1] https://www.publicservice.govt.nz/about-the-commission/gover...
[2] https://www.digital.govt.nz/digital-government/key-areas-of-...