Tight finite-key analysis for mode-pairing quantum key distribution

TL;DR

This paper provides a rigorous finite-key security analysis for mode-pairing quantum key distribution (MP-QKD), demonstrating its practical advantages and proposing an improved six-state protocol for enhanced long-distance performance.

Contribution

It offers the first finite-key security proof for MP-QKD and introduces a six-state protocol that boosts key rates over long distances.

Findings

Original MP-QKD can surpass the repeaterless rate-transmittance bound with finite pulses.

The six-state MP-QKD protocol significantly improves secret key rates in long-distance scenarios.

Finite-key effects are rigorously analyzed for the first time in this context.

Abstract

Mode-pairing quantum key distribution (MP-QKD) is a potential protocol that is not only immune to all possible detector side channel attacks, but also breaks the repeaterless rate-transmittance bound without needing global phase locking. Here we analyze the finite-key effect for the MP-QKD protocol with rigorous security proof against general attacks. Moreover, we propose a six-state MP-QKD protocol and analyze its finite-key effect. The results show that the original protocol can break the repeaterless rate-transmittance bound with a typical finite number of pulses in practice. And our six-state protocol can improve the secret key rate significantly in long distance cases.