Measurement-device-independent quantum key distribution

TL;DR

This paper introduces a measurement-device-independent quantum key distribution method that eliminates detector side channel attacks, doubles secure distance, and is practical with standard optical components, enhancing long-distance quantum cryptography security.

Contribution

It proposes a practical, secure quantum key distribution scheme that removes detector vulnerabilities without requiring advanced detectors or complex quantum non-demolition measurements.

Findings

Removes all detector side channels in QKD

Doubles the secure distance compared to traditional methods

Achieves higher key generation rates than full device independent QKD

Abstract

How to remove detector side channel attacks has been a notoriously hard problem in quantum cryptography. Here, we propose a simple solution to this problem---*measurement* device independent quantum key distribution. It not only removes all detector side channels, but also doubles the secure distance with conventional lasers. Our proposal can be implemented with standard optical components with low detection efficiency and highly lossy channels. In contrast to the previous solution of full device independent QKD, the realization of our idea does not require detectors of near unity detection efficiency in combination with a qubit amplifier (based on teleportation) or a quantum non-demolition measurement of the number of photons in a pulse. Furthermore, its key generation rate is many orders of magnitude higher than that based on full device independent QKD. The results show that long-distance quantum cryptography over say 200km will remain secure even with seriously flawed detectors.