Maybe, it's possible to embed RF information into natural sounds that are transmitted undetectable but remain extractable at the receiving end with special keys that are changeable. I suppose the keys could be transmitted in a similar manner. If just one aspect of the transmissions escapes detection, then unauthorized decoding would be extremely difficult. Music might be a good case for experimentation.
Optical Transmission in a Mobile Environment:
http://spie.org/x8534.xml?highlight=x2414
Optical Transmission in a Mobile Environment:
http://spie.org/x8534.xml?highlight=x2414
Last edited: