Yiming Bian

A coherent-state point-to-multipoint protocol is proposed to simultaneously support multiple independent quantum key distribution links between a single transmitter and massive receivers. Every prepared coherent state is measured by all receivers to generate raw keys, then processed with a secure and high-efficient key distillation method to remove the correlations between different links. The simulation results show that it can achieve remarkably high key rates even with a hundred of access points. Further, a proof-of-principle experiment with one network node and four end users has been demonstrated, where the average secret key rate of 4.1 Mbps between the transmitter and each one receiver is achieved, resulting in two orders-of-magnitude higher than previous networks. This scheme is a promising step towards a high-rate multi-user solution in a scalable quantum secure network.

We report a unidimensional two-way continuous-variable quantum key distribution protocol, which shows the potential of secure communication with simple modulation method in noisy situations.