A system to control access to at least one protected device, the system comprising a test access port operable to mate with an external key device and an internal key device that is operable to receive synchronized cipher words during an idle state of the test access port from a removable external key device. The internal key device is also operable to receive test signals via the external key device and to input the received test signals to the protected device based on the synchronized cipher words. The protected device and the internal key device are one of located within a closed chassis, located under a protective security coating, located within a multi-chip-module, located within a closed integrated circuit package, and combinations thereof.