Recently some alternatives of the measurement device independent quantum key distribution(MDI-QKD) based on the single-photon Bell state measurement (SBSM) have been proposed. Although these alternatives are not precisely as secure as MDI-QKD, they possess the advantage of high key rate of traditional BB84-like protocol and avoid the technical complexity of two-photon interference required in the MDI-QKD. However, the setups of these proposed schemes are rather complicated compared to commonly used BB84 systems. Here we propose a simple implementation of SBSM-based QKD which is directly built on the existing realization of BB84 QKD. Our proposal exhibits the hidden connection between SBSM-based QKD and traditional phase-coding QKD protocols. This finding discloses the physics behind these two different types of QKD protocols. In addition, we experimentally demonstrate the feasibility of our protocol.
@article{arxiv.1505.00897,
title = {A simple implementation of quantum key distribution based on single-photon Bell state measurement},
author = {Wen-Ye Liang and Mo Li and Zhen-Qiang Yin and Wei Chen and Shuang Wang and Xue-Bi An and Guang-Can Guo and Zheng-Fu Han},
journal= {arXiv preprint arXiv:1505.00897},
year = {2015}
}