Measurement-Device-Independent Quantum Key Distribution with Two-Way Local Operations and Classical Communications**Supported by the National Natural Science Foundation of China under Grant No 61378011, and the Program for Science and Technology Innovation Research Team in University of Henan Province under Grant No 13IRTSTHN020.

Abstract

Measurement-device-independent quantum key distribution (MDI-QKD) is proven to be immune to all the detector side channel attacks. With two symmetric quantum channels, the maximal transmission distance can be doubled when compared with the prepare-and-measure QKD. An interesting question is whether the transmission distance can be extended further. In this work, we consider the contributions of the two-way local operations and classical communications to the key generation rate and transmission distance of the MDI-QKD. Our numerical results show that the secure transmission distances are increased by about 12 km and 8 km when the 1 B and the 2 B steps are implemented, respectively.