Decoy-state quantum key distribution with two-way classical postprocessing
Xiongfeng Ma, Chi‐Hang Fred Fung, Frédéric Dupuis, Kai Chen, Kiyoshi Tamaki, Hoi‐Kwong Lo · Physical Review A · 2006
Decoy states have recently been proposed as a useful method for substantially improving the performance of quantum key distribution (QKD) protocols when a coherent-state source is used. Previously, data postprocessing schemes based on one-way classical communications were considered for use with decoy states. In this paper, we develop two data postprocessing schemes for the decoy-state method using two-way classical communications. Our numerical simulation (using parameters from a specific QKD experiment as an example) results show that our scheme is able to extend the maximal secure distance from $142\phantom{\rule{0.3em}{0ex}}\mathrm{km}$ (using only one-way classical communications with decoy states) to $181\phantom{\rule{0.3em}{0ex}}\mathrm{km}$. The second scheme is able to achieve a 10% greater key generation rate in the whole regime of distances. We conclude that decoy-state QKD with two-way classical postprocessing is of practical interest.