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arXiv · 2604.27943

Adaptable Continuous Variable Quantum Network with Finite Size Security

Runjia Zhang·Akash nag Oruganti·Huy Q. Nguyen·Ivan Derkach·Adnan A. E. Hajomer·Vladyslav C. Usenko·Ulrik L. Andersen·Tobias Gehring
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Abstract

In recent years, continuous-variable quantum key distribution (CV-QKD) has become a promising paradigm for enabling secure communication among multiple end users sharing the same telecommunication backbone. CV-QKD with reverse reconciliation naturally enables scalability from conventional point-to-point links to quantum access networks based on passive quantum broadcasting channels. Here, we report an experimental demonstration on an active $1:4$ multi-user CV quantum network (QN) in the finite-size regime. With $1.25\cdot10^9$ coherent states exchanged on each $11\text{km}$ quantum channel, the highest performance for secret key generation totaling $1.9\cdot10^{-1}$ bits/channel use. Furthermore, we investigate adaptable CV-QN protocols that comprehensively allow network operation in various security and key rates requirements of individual users. The results establish the practical security of CV-QN compatible with existing telecommunication for broad deployment, and allowing additional degree of freedom for connected end users in existing infrastructures.

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Runjia Zhang, Akash nag Oruganti, Huy Q. Nguyen, Ivan Derkach, Adnan A. E. Hajomer, Vladyslav C. Usenko, Ulrik L. Andersen, Tobias Gehring. 2026-04-30. Adaptable Continuous Variable Quantum Network with Finite Size Security. https://arxiv.org/abs/2604.27943

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