Five-user QKD over switched fiber networks
Jan Bogdanski, Nima Rafiei, Mohamed Bourennane · 2008
Unconditionally secure multiuser quantum key distribution (QKD) over long distance switched telecom fiber networks will have a revolutionary impact on people's, companies', and governmental exchange of confidential information. We report five-user QKD over switched fiber networks in both star and tree configurations, using the BB84-protocol with phase encoding. Both setups implement polarization insensitive phase modulators, necessary for birefringent single mode fiber networks. In both configurations, for the mean photon number μ=0.1, we have achieved raw rates between 50Hz and 300Hz at distances between 25km to 50km with quantum bit error rates between 1.24% to 5.56%. The measurements have showed feasibility of multiuser QKD over switched telecom fiber networks, using standard fiber telecom components.