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arXiv · 1805.10314

Security-proof framework for two-way Gaussian quantum-key-distribution protocols

Quntao Zhuang·Zheshen Zhang·Norbert Lütkenhaus·Jeffrey H. Shapiro
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Abstract

Two-way Gaussian protocols have the potential to increase quantum key distribution (QKD) protocols' secret-key rates by orders of magnitudes~[Phys.~Rev.~A {\bf 94}, 012322 (2016)]. Security proofs for two-way protocols, however, are underdeveloped at present. In this paper, we establish a security proof framework for the general coherent attack on two-way Gaussian protocols in the asymptotic regime. We first prove that coherent-attack security can be reduced to collective-attack security for all two-way QKD protocols. Next, we identify two different constraints that each provide intrusion parameters which bound an eavesdropper's coherent-attack information gain for any two-way Gaussian QKD protocol. Finally, we apply our results to two such protocols.

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Quntao Zhuang, Zheshen Zhang, Norbert Lütkenhaus, Jeffrey H. Shapiro. 2018-05-25. Security-proof framework for two-way Gaussian quantum-key-distribution protocols. https://doi.org/10.1103/physreva.98.032332

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