Memory-assisted measurement-device-independent quantum secret sharing

Abstract

Measurement-device-independent quantum secret sharing (MDI-QSS) can resist all attacks on imperfect measuring devices. However, limited by the exponential increase in fiber loss, MDI-QSS has a low key rate and short communication distance. In this paper, we introduce quantum memory (QM) in MDI-QSS to increase the success probability of the three-photon synchronous projection measurement and propose a memory-assisted (MA) MDI-QSS protocol. In this protocol, the heralded single-photon source and the decoy-state method are also explored. This MA-MDI-QSS protocol has three advantages. First, the QM used here is all optical, and this protocol is feasible under current experimental conditions. Second, combined with the decoy-state method, our protocol can guarantee the security of the transmitted keys under practical experimental conditions. Third, numerical simulation results show that our protocol has a higher secure key rate and longer photon transmission distance than existing MDI-QSS protocols without QM. Our protocol provides a promising way for implementing the long-distance MDI-QSS in the near future.