Sending Sensitive Messages in Quantum Packages
  A communication protocol is introduced that allows the receiver of a message to place an a posteriori bound on the amount of information that an eavesdropper could have obtained during transmission of that message. This quantum cryptographic protocol is distinct from quantum key distribution. The quantum states and measurements required by this protocol are simple enough that it can be implemented using existing technology. 
Paul A. Lopata, Thomas B. Bahder