ZeFi used a third-party service Tor.us for key management as well as o-auth integration.
Torus is a key management solution that aims to provide seamless access to DApps.
How does Torus work?
Torus splits a user’s private keys across a network of nodes and allows a user to retrieve this using natural login mechanisms like social authentication.
Users' keys are generated in a distributed manner* amongst an MPC (Multi-Party Computing) network of nodes and are only reconstructed when successfully authenticated on the client-side. Torus' distributed key generation system is governed on the Ethereum Smart Contract layer.