A Proposed System for Covert Communication to Distant and Broad   Geographical Areas
  A covert communication system is developed that modulates Morse code characteristics and that delivers its mes- sage economically and to geographically remote areas using radio and EchoLink. Our system allows a covert message to be sent to a receiving individual by hiding it in an existing carrier Morse code message. The carrier need not be sent directly to the receiving person, though the receiver must have access to the signal. Illustratively, we propose that our system may be used as an alternative means of implementing numbers stations. 
Joshua Davis
cs.CR