This is a great idea. If protonmail had this, I'd switch over to it (the paid version) today.
> I suspect that the encryption on the contacts would prevent a normal CardDAV implementation from being possible.
Protonmail clearly doesn't use passwords to derive encryption keys for contacts (as they allow for password recovery), so they have the ability to encrypt/decrypt contacts on disk. A Carddav server would be technically feasible, and the spec is pretty straightforward.
Anonymous
This is a great idea. If protonmail had this, I'd switch over to it (the paid version) today.
> I suspect that the encryption on the contacts would prevent a normal CardDAV implementation from being possible.
Protonmail clearly doesn't use passwords to derive encryption keys for contacts (as they allow for password recovery), so they have the ability to encrypt/decrypt contacts on disk. A Carddav server would be technically feasible, and the spec is pretty straightforward.