Abstract: Security registration and authentication systems and methods are disclosed herein for extending OpenID security standards for registration of OpenID client devices for passkey authentication. A client device comprises client frontend application (app). A registration and authentication server comprises a client backend app for receiving an authorization request of the client device comprising a prompt parameter, and implementing one of: (a) a secure registration algorithm if the prompt parameter defines a create value; or (b) an authentication algorithm if the prompt parameter does not define the create value. The security registration and authentication systems and methods provide an authentication token to the client device, the authentication token authenticating the client device to initiate a secure session with a secure resource on a computer network.