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arXiv · 2411.17547

Distance-Security Tradeoffs for Repeaterless End-to-End QKD Networks

Sumit Chaudhary·Davide Li Calsi·JinHyeock Choi·Marc Geitz·Janis Nötzel
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Abstract

Quantum Key Distribution (QKD) offers provably secure, information-theoretic key exchange, but in long-distance scenarios without quantum repeaters, Trusted Nodes (TNs) are commonly employed despite introducing critical security risks. We propose a redundant key management method for QKD network that combines Twin Field QKD (TF-QKD) (or Measurement-Device Independent (MDI)-QKD) with a novel key-routing scheme to eliminate the need for truly trusted TNs. Quantum measurements are handled entirely within the network, minimizing end-user hardware requirements. Multiple QKD links connect intermediate nodes such that a successful attack requires the collusion of multiple adversarial nodes, greatly enhancing security over the traditional TN model. In this contribution, we discuss the tradeoff between security, key rates, and distances supported by the new method. Our analysis reveals that the improved redundant key management system may enable true end-to-end connectivity over several thousand kilometers while maintaining high security standards.

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Sumit Chaudhary, Davide Li Calsi, JinHyeock Choi, Marc Geitz, Janis Nötzel. 2024-11-26. Distance-Security Tradeoffs for Repeaterless End-to-End QKD Networks. https://arxiv.org/abs/2411.17547

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