An apparatus and method for authentication having a processor and at least
one activator coupled to the processor is claimed. A signature generator
is coupled to the processor and capable of generating a secure
identifier. An emitter coupled to the signal generator capable of
emitting the secure identifier. A receiver receives the emitted secure
identifier and verifies that the secure identifier was appropriately
transmitted. The public key corresponding to the key identifier
transmitted is accessed to determine the validity of the secure
identifier using the accessed key and that the time indicated in the
received secure identifier is verified to be within acceptable time
tolerances.