Measurement-device-independent quantum secret sharing with hyper-encoding

Quantum secret sharing(QSS) is a typical multi-party quantum communication mode, in which the key sender splits a key into several parts and the participants can obtain the key by cooperation. Measurement-device-independent quantum secret sharing(MDI-QSS) is immune to all possible attacks from measurement devices and can greatly enhance QSS's security in practical applications. However, previous MDI-QSS's key generation rate is relatively low. Here, we adopt the polarization-spatial-mode hyper-encoding technology in the MDI-QSS, which can increase single photon's channel capacity. Meanwhile, we use the cross-Kerr nonlinearity to realize the complete hyper-entangled Greenberger-Horne-Zeilinger state analysis. Both above factors can increase MDI-QSS's key generation rate by about 10^(3). The proposed hyper-encoded MDI-QSS protocol may be useful for future multiparity quantum communication applications.

High-capacity device-independent quantum secure direct communication based on hyper-encoding

Quantum secure direct communication(QSDC)can directly transmit secret messages through quantum channel without keys.Device-independent(DI)QSDC guarantees the message security relying only on the observation of the Bell-inequality violation,but not on any detailed description or trust of the devices'inner workings.Compared with conventional QSDC,DI-QSDC has relatively low secret message capacity.To increase DI-QSDC's secret messages capacity,we propose a high-capacity DI-QSDC protocol based on the hyper-encoding technique.The total message leakage rate of our DI-QSDC protocol only relies on the most robust degree of freedom.We provide the numerical simulation of its secret message capacity altered with the communication distance.Our work serves as an important step toward thefurther development of DI-QSDC systems.