Efficient decoy states for the reference-frame-independent measurement-device-independent quantum key distribution
Feng-Yu Lu, Zhen−Qiang Yin, Guan‐Jie Fan‐Yuan, Rong Wang, Hang Liu, Shuang Wang, Wei Chen, De‐Yong He, Wei Huang, Bingjie Xu, Guang‐Can Guo, Zheng‐Fu Han
Abstract
Reference-frame-independent measurement-device-independent quantum key distribution (RFI-MDI-QKD) is a novel protocol that eliminates all possible attacks on the detector side and the necessity of reference-frame alignment in source sides. However, its performance may degrade notably due to statistical fluctuations since more parameters, e.g., yields and error rates for mismatched-basis events, must be accumulated to monitor the security. In this work, we find that the original decoy states method estimates these yields overpessimistically since it ignores the potential relations between different bases. Through jointly processing parameters of different bases, the performance of RFI-MDI-QKD is greatly improved in terms of the secret key rate and achievable distance when statistical fluctuations are considered (the statistical fluctuation analysis is the first step to the final analysis of the finite key size effect). Our results pave an avenue towards practical RFI-MDI-QKD.