Enhanced key-establishing rates and efficiencies in fiber laser key distribution systems

The secure key-establishing efficiency of an ultra-long fiber laser key distribution system (UFL-KDS) is limited by half a key bit per cycle. We purpose and analyze novel schemes and protocols for breaking this limit while retaining system security. These schemes increase the probability of a secure bit transition by expanding the variable and coding parameters of the UFL-KDS. Furthermore, a new wavelength division multiplexing UFL implementation, which enables an additional key-establishing rate enhancement, is proposed and analyzed. These schemes further emphasize the potential in the UFL concept, in particular its security and its practical implementation properties.