Unbalanced-basis-misalignment tolerant measurement-device-independent quantum key distribution

TL;DR

This paper introduces a measurement-device-independent quantum key distribution protocol that is tolerant to source misalignments, reducing assumptions on encoding and demonstrating high performance and security in practical and network scenarios.

Contribution

It presents a new MDIQKD protocol requiring less knowledge of the encoding system, enhancing robustness against modulation errors and fluctuations, with experimental validation.

Findings

High-performance security demonstrated experimentally

Robustness against modulation errors confirmed

Suitable for complex QKD network scenarios

Abstract

Measurement-device-independent quantum key distribution (MDIQKD) is a revolutionary protocol since it is physically immune to all attacks on the detection side. However, the protocol still keeps the strict assumptions on the source side that the four BB84-states must be perfectly prepared to ensure security. Some protocols release part of the assumptions in the encoding system to keep the practical security, but the performance would be dramatically reduced. In this work, we present a MDIQKD protocol that requires less knowledge of encoding system to combat the troublesome modulation errors and fluctuations. We have also experimentally demonstrated the protocol. The result indicates the high-performance and good security for its practical applications. Besides, its robustness and flexibility exhibit a good value for complex scenarios such as the QKD networks.