Abstract: A resource allocator (108) receives, from a first communication unit, a request to establish secure communications with at least a second communication unit. A key identifier is retrieved by the resource allocator and transmitted to at least the second communication unit. Based upon the transmitted key identifier, the second communication unit retrieves an identified encryption key and, at least when the identified encryption key is corrupt, transmits a corrupt key indication to the resource allocator. In response, the resource allocator can assign a default key identifier for use in the secure communication. In this manner, missed communications due to encryption key failures are reduced.

Abstract: In a secure trunked communication system that includes a central controller, communication between a distribution panel and a limited number of console interface units may be achieved in the following manner. At power up or upon a reset condition, the distribution panel transmits a status check message to each console interface unit in the system. Console interface units that are active respond by transmitting an acknowledgement. Upon receiving the acknowledgement, the distribution panel transmits the addresses of the active console interface units to the central controller. When the distribution panel receives secure information from the central controller, it interprets the information to identify a target console interface unit and transmits the received secure information to the target console interface unit.