https://www.youtube.com/watch?v=PKtklN8mOo0
https://media.ccc.de/v/38c3-eu-s-digital-identity-systems-reality-check-and-techniques-for-better-privacy
Very interesting talk about the cryptographical systems that could allow fully private and anonymous authentication.
This would actually be way more private than today, with deniability preventing data-sharing.
It looks like the necessary technology to help against identity theft.
This is done in devices secure elements, and hardware limitations are a big problem here.