Practical Quantum Key Distribution Secure Against Side-Channels

TL;DR

This paper introduces a practical measurement-device-independent quantum key distribution protocol that is secure against side-channels and device imperfections, using a simple setup with coherent light, bridging the gap between theory and real-world implementation.

Contribution

The authors propose a new MDI-QKD protocol based on coherent light that is secure against all transmitter side-channels and simplifies experimental requirements.

Findings

Protocol is secure against any transmitter side-channel.

Performance is comparable to existing MDI-QKD protocols.

Experimental setup is simplified with only one parameter needed.

Abstract

There is a big gap between theory and practice in quantum key distribution (QKD) because real devices do not satisfy the assumptions required by the security proofs. Here, we close this gap by introducing a simple and practical measurement-device-independent (MDI) QKD type of protocol, based on the transmission of coherent light, for which we prove its security against any possible device imperfection and/or side-channel at the transmitters' side. Besides using a much simpler experimental set-up and source characterization with only one single parameter, we show that the performance of the protocol is comparable to other MDI-QKD type of protocols which disregard the effect of several side-channels.