Improvement Measurement-Device-Independent Quantum Key Distribution with Imperfect Coherent Pulses

Abstract

Abstract The security of the original measurement-device-independent quantum key distribution (MDI-QKD), immune to all possible side channel detector attacks, is relied on the assumption that legitimate users, called Alice and Bob, can control their sources exactly. However, this might always not be satisfied in today’s state of the art. Later, one of us has proposed a MDI-QKD with uncharacterized coherent pulses, and shows that MDI-QKD can cover long distances securely with imperfect current sources. In this paper, relied on the basic imperfect sources assumption of the former work, we propose an improved one by applying a technique of imperfect phase region matching. We focus on deriving the bound of secrete key rate for this improved protocol, and simulation results show that the improved MDI-QKD can achieve much more better performances than the former one. It pushes the MDI-QKD a step forward to be more practical in more device independent scenario.