User authentication via mobile communication device with imaging system

A graphical authentication identifier is used to facilitate automatic authentication of a user. A graphical identifier authentication system receives a request from an authenticating entity for a onetime use graphical authentication identifier. In response to the received request, a onetime use graphical authentication identifier to be displayed by the authenticating entity is generated. A request for user authentication information by the authenticating entity is encoded in the graphical authentication identifier, which is transmitted to the authenticating entity for display (e.g., on a login screen). The onetime use graphical authentication identifier being displayed by the authenticating entity is captured by a registered user operated computing device. In response, the requested user authentication information is transmitted to the authenticating entity, such that the user is automatically authenticated to the authenticating entity, without the user manually entering the requested user authentication information.