Patent ID: 8607318

Claim:
An active slave device for a Bluetooth system, the active slave device comprising: a non-volatile memory unit for storing a plurality of link keys corresponding to a master device capable of switching among a plurality of operating modes, wherein the plurality of link keys correspond to the plurality of operating modes and are generated by a key pairing procedure performed between the active slave device and the master device when the master device operates in the plurality of operating modes; and a key fishing unit for searching whether any of the plurality of link keys conforms to a qualified link key that can enable the active slave device under the current operating mode of the master device without another key pairing procedure performed between the active slave device and the master device; wherein the non-volatile memory unit stores the plurality of link keys in a storage format comprising a pairing Bluetooth address field for storing a Bluetooth address that has ever been paired successfully, a link key field for storing one of the plurality of link keys corresponding to the Bluetooth address, and a valid field for representing whether the one corresponding link key is valid, wherein a default value of the one corresponding link key is invalid.