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arXiv · 2601.06772

Experimental Coherent One-Way Quantum Key Distribution with Simplicity and Practical Security

Xiao-Yu Cao·Xiao-Ran Sun·Ming-Yang Li·Yu-Shuo Lu·Hua-Lei Yin·Zeng-Bing Chen
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Abstract

Coherent one-way quantum key distribution (COW-QKD) has been widely investigated, and even been deployed in real-world quantum network. However, the proposal of the zero-error attack has critically undermined its security guarantees, and existing experimental implementations have not yet established security against coherent attacks. In this work, we propose and experimentally demonstrate an information-theoretically secure COW-QKD protocol that can resist source side-channel attacks, with secure transmission distances up to 100 km. Our system achieves a secure key rate on the order of kilobits per second over 50 km in the finite-size regime, sufficient for real-time secure voice communication across metropolitan networks. Furthermore, we demonstrate the encrypted transmission of a logo with information-theoretic security over 100 km of optical fiber. These results confirm that COW-QKD can simultaneously provide simplicity and security, establishing it as a strong candidate for deployment in small-scale quantum networks.

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Xiao-Yu Cao, Xiao-Ran Sun, Ming-Yang Li, Yu-Shuo Lu, Hua-Lei Yin, Zeng-Bing Chen. 2026-01-11. Experimental Coherent One-Way Quantum Key Distribution with Simplicity and Practical Security. https://doi.org/10.1126/sciadv.aec2776

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