Embodiments of the present disclosure provide a method and system for authenticating communication between a plurality of accessory devices or services and one or more media devices by using a single authentication processor. The method includes the steps of establishing a communication of a media device attached to an accessory device with an authentication processor through an authentication processor manager, authenticating the accessory device by the media device based on a digital certificate and a digital signature; and authenticating the media device by the accessory device based on verification of the digital certificate and the digital signature.