An improved bolt and bolt carrier with integral gas key having an extension nozzle threadedly secured and pinned to the gas key for use with a direct gas operated firearm is provided. Software executes under expected usage conditions. The reduction in power consumption may be achieved by forming distinct layers of phase change material that have little or no mixing between them outside the programmed volume. Peer-A and Peer-B reciprocally store message identification including sequence number and timestamp in a local session record contained in a secure memory.