U2F Technical Overview
https://developers.yubico.com/U2F/Protocol_details/Overview.html [developers.yubico.com]
2019-04-24 21:45
U2F is a challenge-response protocol extended with phishing and MitM protection, application-specific keys, device cloning detection and device attestation. There are two flows: registration and authentication.
For the full package of FIDO U2F specifications, visit the FIDO Alliance Specifications homepage.