Communication between host and accessory devices using accessory protocols via wireless transport

An accessory can communicate wirelessly with a host device such as a portable electronic device. Existing accessory protocols developed for wired communication can be used without modification, and a wireless network connecting the two devices can provide a transport or channel connecting the two devices. Establishing a wireless channel can involve the active participation of both devices. For instance, the host device can create and identify virtual port to be used by the accessory, after which the accessory can initiate communication on that virtual port. A host device can be configured to automatically connect to certain accessories upon detection of that accessory on a wireless network under various specific conditions. Encryption of accessory-protocol communications between an accessory and a host device is also provided.