Composable security analysis of continuous-variable measurement-device-independent quantum key distribution with squeezed states for coherent attacks

TL;DR

This paper provides the first composable security analysis for continuous-variable measurement-device-independent quantum key distribution with squeezed states, demonstrating its robustness against coherent attacks and finite-size effects.

Contribution

It introduces a novel security analysis framework for CV-MDI-QKD with squeezed states, considering finite-size effects and general coherent attacks.

Findings

Protocol tolerates 2.5 dB channel loss with direct reconciliation.

Protocol tolerates 6.5 dB channel loss with reverse reconciliation.

Security analysis is based on entanglement-based scheme and entropic uncertainty relations.

Abstract

Measurement-device-independent quantum key distribution protocol, whose security analysis does not rely on any assumption on the detection system, can immune the attacking against detectors. We give a first composable security analysis for continuous-variable measurement-device-independent quantum key distribution using squeezed states against general coherent attacks. The security analysis is derived based on the entanglement-based scheme considering finite size effect. A version of entropic uncertainty relation is exploited to give a lower bound on the conditional smooth min-entropy by trusting Alice's and Bob's devices. The simulation results indicate that, in the universal composable security framework, the protocol can tolerate 2.5 dB and 6.5 dB channel loss against coherent attacks with direct and reverse reconciliation, respectively.