An accessory communication control protocol can facilitate faster and more secure transmission of status updates from an accessory to a controller (or network base station). An accessory can register with a controller, where the controller can provide some subscription and key generation information to the accessory. The accessory can detect changes to characteristics of the accessory and generate a broadcast notification that includes updates to the state of the characteristic. The broadcast notification can also include a counter, a device identifier, and a key. According to timing or rules, the accessory can transmit the broadcast notification to the controller without the need to establish a secure session with the controller.