1. Overview OpenOTP supports FIDO2 standard from the FIDO Alliance for user authentication and Passkeys provided by Google or Apple. If you intend to use OpenOTP with FIDO2 or Passkeys, please read this document which explains how to enable and use it with your integrations. 1.1 FIDO2 FIDO2 enables users to leverage common devices to easily authenticate to online services in both mobile and desktop environments. The FIDO2 specifications are the World Wide Web Consortium’s (W3C) Web Authentication (WebAuthn) specification and FIDO Alliance’s corresponding Client-to-Authenticator Protocol (CTAP).