Quantum direct communication with continuous variables

Quantum direct communication with continuous variables

Pirandola, S., Braunstein, S.L., Mancini, S. and Lloyd, S.
(2008): Euro Physics Letters 84, 20013-1/6 (PDF)

ABSTRACT: We show how continuous-variable systems can allow the direct communication of messages with an acceptable degree of privacy. This is possible by combining a suitable phase-space encoding of the plain message with real-time checks of the quantum communication channel. The resulting protocol works properly when a small amount of noise affects the quantum channel. If this noise is non-tolerable, the protocol stops leaving a limited amount of information to a potential eavesdropper.