A method, system, and connector interface for authenticating an accessory. The method includes performing a first authentication operation on the accessory by the media player, where an authentication certificate is validated; and performing a second authentication operation on the accessory by the media player, where an authentication signature is validated. According to the system and method disclosed herein, the media player and accessory may utilize a plurality of commands in a variety of environments such as within a connector interface system environment to control access to the media player.