PreprintarXiv licencearXiv
Decoy-state quantum key distribution with a leaky Mach-Zehnder receiver
Abstract
We prove the security of phase-encoded decoy-state BB84 quantum key distribution for a Mach-Zehnder receiver with imbalanced beam splitters and two threshold detectors that leak fine-grained information about the detection patterns. For this, we derive a lower bound on Bob's single-photon contributions and combine it with the decoy-state method and a recent phase-error framework for leaky receivers. The leakage-induced correction to the phase-error rate is independent of channel loss, providing a loss-tolerant treatment of receiver leakage even in the presence of beam-splitter imbalance. Our results provide a practical route toward loss-tolerant security proofs for imperfect QKD receivers in the presence of receiver leakage.
Related
- Coherent receiver for Continuous-Variable Quantum Key Distribution using a 3 × 3 beam splitter and single-ended photodetectors
- Distributed quantum phase sensing using an SU(1,1) Perelomov coherent state in a Mach-Zehnder interferometer network
- Decoy-state optical quantum information processing with coherent states
- A robust digital receiver architecture for continuous-variable quantum key distribution
- From Received Power to Certified Secret Keys: A General Method for Bridging Classical FSO Link Budgets and Decoy-State QKD
BibTeX
@misc{mizusawa2026decoystate,
title = {{Decoy-state quantum key distribution with a leaky Mach-Zehnder receiver}},
author = {Ryohei Mizusawa and Álvaro Navarrete and Akihiro Mizutani and Kiyoshi Tamaki},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.04539},
eprint = {2611.04539},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.04539},
}
RIS
TY - UNPB
TI - Decoy-state quantum key distribution with a leaky Mach-Zehnder receiver
AU - Ryohei Mizusawa
AU - Álvaro Navarrete
AU - Akihiro Mizutani
AU - Kiyoshi Tamaki
PY - 2026
DA - 2026/11/03
PB - arXiv
DO - 10.48550/arxiv.2611.04539
UR - https://arxiv.org/abs/2611.04539
AB - We prove the security of phase-encoded decoy-state BB84 quantum key distribution for a Mach-Zehnder receiver with imbalanced beam splitters and two threshold detectors that leak fine-grained information about the detection patterns. For this, we derive a lower bound on Bob's single-photon contributions and combine it with the decoy-state method and a recent phase-error framework for leaky receivers. The leakage-induced correction to the phase-error rate is independent of channel loss, providing a loss-tolerant treatment of receiver leakage even in the presence of beam-splitter imbalance. Our results provide a practical route toward loss-tolerant security proofs for imperfect QKD receivers in the presence of receiver leakage.
ER -