Secret Key Distribution Protocol for Practical Optical Channels Using a Preshared Key and Phase Fluctuations

Tatsuya Tomaru
2010 Japanese Journal of Applied Physics  
A practical secret-key-distribution protocol using general phase fluctuations is described. A preshared key is assumed and is used only inside a transmitter and a receiver. The probabilistic property of signal-light fluctuations works with the preshared key to produce a difference in bit-error rate between a receiver and an eavesdropper. Using the difference, new secret keys are generated information theoretically although a preshared key is used. The probabilistic property of signal-light
more » ... uations is essential in this protocol, and classical fluctuations as well as quantum fluctuations are applicable. Because signal states are classical, the system becomes tolerant of loss and amplification.
doi:10.1143/jjap.49.074401 fatcat:evit3nmf2jfp3pk4rz5xb3yehm