Making the decoy-state measurement-device-independent quantum key distribution practically useful

TL;DR

This paper introduces a 4-intensity decoy-state MDIQKD protocol that significantly increases key rates and enables near real-time secure communication, addressing a major practical barrier.

Contribution

A novel 4-intensity protocol for decoy-state MDIQKD that enhances key rates and reduces delay for secure key generation.

Findings

Key rate is substantially increased with the new protocol.

Secure keys can be generated within a few seconds.

Practical implementation of MDIQKD becomes more feasible.

Abstract

The relatively low key rate seems to be the major barrier to its practical use for the decoy state measurement device independent quantum key distribution (MDIQKD). We present a 4-intensity protocol for the decoy-state MDIQKD that hugely raises the key rate, especially in the case the total data size is not large. Also, calculation shows that our method makes it possible for secure private communication with {\em fresh} keys generated from MDIQKD with a delay time of only a few seconds.