BidiPass (BDP) describes itself as an identity authentication protocol built on Ethereum.

The BidiPass Authenticator aims to offer decentralized 3FA for enhanced infrastructure security. The BidiPass platform aims to offer a user-friendly, secure, and reliable method to authorize actions within connected platforms (e.g. approving transactions on a trading platform) by using a two-layer security protocol that operates in a distributed, peer-to-peer manner. The BidiPass blockchain architecture is based on a hybrid approach which combines private and public blockchains in order to achieve security, performance, and low operational costs.

BidiPass's goal is to create a solution that will adapt to technological innovations and greater infrastructure security in the long term. More information here: https://bidipass.org/