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arXiv · 2210.08183

Security of quantum key distribution with imperfect phase randomisation

Guillermo Currás-Lorenzo·Shlok Nahar·Norbert Lütkenhaus·Kiyoshi Tamaki·Marcos Curty
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Abstract

The performance of quantum key distribution (QKD) is severely limited by multiphoton emissions, due to the photon-number-splitting attack. The most efficient solution, the decoy-state method, requires that the phases of all transmitted pulses are independent and uniformly random. In practice, however, these phases are often correlated, especially in high-speed systems, which opens a security loophole. Here, we address this pressing problem by providing a security proof for decoy-state QKD with correlated phases that offers key rates close to the ideal scenario. Our work paves the way towards high-performance secure QKD with practical laser sources, and may have applications beyond QKD.

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Guillermo Currás-Lorenzo, Shlok Nahar, Norbert Lütkenhaus, Kiyoshi Tamaki, Marcos Curty. 2022-10-15. Security of quantum key distribution with imperfect phase randomisation. https://doi.org/10.1088/2058-9565%2Fad141c

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