Simple security proof of coherent-one-way quantum key distribution

Abstract

Coherent-one-way quantum key distribution (COW-QKD), which requires a simple experimental setup and has the ability to withstand photon-number-splitting attacks, has been not only experimentally implemented but also commercially applied. However, recent studies have shown that the current COW-QKD system is insecure and can only distribute secret keys safely within 20 km of the optical fiber length. In this study, we propose a practical implementation of COW-QKD by adding a two-pulse vacuum state as a new decoy sequence. This proposal maintains the original experimental setup as well as the simplicity of its implementation. Utilizing detailed observations on the monitoring line to provide an analytical upper bound on the phase error rate, we provide a high-performance COW-QKD asymptotically secure against coherent attacks. This ensures the availability of COW-QKD within 100 km and establishes theoretical foundations for further applications.

8 pages, 5 figures, 1 table, Typos corrected

References in corpus (9)

• Hacking commercial quantum cryptography systems by tailored bright illumination
• Measurement device independent quantum key distribution over 404 km optical fibre
• Provably Secure and Practical Quantum Key Distribution over 307 km of Optical Fibre
• Provably-Secure and High-Rate Quantum Key Distribution with Time-Bin Qudits
• Experimental quantum key distribution beyond the repeaterless secret key capacity
• Direct and Reverse Secret-Key Capacities of a Quantum Channel
• Squashing Models for Optical Measurements in Quantum Communication
• Modulator-free coherent-one-way quantum key distribution
• Security of quantum key distribution with multiphoton components

Cited by in corpus (9)

• High-dimensional coherent one-way quantum key distribution
• Finite-Key Analysis for Coherent One-Way Quantum Key Distribution
• Quantum key distribution based on orthogonal state encoding
• Experimental Coherent One-Way Quantum Key Distribution with Simplicity and Practical Security
• Hacking coherent-one-way quantum key distribution with present-day technology
• Simulations of distributed-phase-reference quantum key distribution protocols
• High-Fidelity Coherent-One-Way QKD Simulation Framework for 6G Networks: Bridging Theory and Reality
• Photonic quantum information with time-bins: Principles and applications
• Increasing the secret key rates and point-to-multipoint extension for experimental coherent-one-way quantum key distribution protocol