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Secure quantum key distribution

Abstract

Secure communication is crucial in the Internet Age, and quantum mechanics stands poised to revolutionize cryptography as we know it today. In this Review, we introduce the motivation and the current state of the art of research in quantum cryptography. In particular, we discuss the present security model together with its assumptions, strengths and weaknesses. After briefly introducing recent experimental progress and challenges, we survey the latest developments in quantum hacking and countermeasures against it.

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Figure 1: Progress in free-space QKD implementations.
Figure 2: Experimental QKD.
Figure 3: QKD networks.
Figure 4: Examples of quantum hacking.
Figure 5: Examples of countermeasures against quantum hacking.

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Acknowledgements

The authors thank K. Azuma, C. H. Bennett, M. Fujiwara, G. Kato, N. Matsuda, N. Namekata, T. Ochi, B. Qi, L. Qian, M. Sasaki, H. Shibata, H. Takesue, F. Xu, K. Yoshino, Q. Zhang, Y. Zhao and the anonymous referees for their valuable comments and suggestions. We specially thank C. H. Bennett and R. J. Hughes for allowing us to use photographs of the first experimental demonstration of QKD and of the first-generation, modularly integrated QKarD respectively in this Review. We thank Z. Tang for technical support in formatting our manuscript. We acknowledge support from the European Regional Development Fund (ERDF), the Galician Regional Government (projects CN2012/279 and CN 2012/260, “Consolidation of Research Units: AtlantTIC”), NSERC, the CRC program, the Connaught Innovation Award, and the project “Secure Photonic Network Technology” as part of the project UQCC by the National Institute of Information and Communications Technology (NICT) of Japan, as well as from the Japan Society for the Promotion of Science (JSPS) through its Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST Program).

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Correspondence to Hoi-Kwong Lo, Marcos Curty or Kiyoshi Tamaki.

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H.-K.L. is a named inventor on US Patent #8,554,814, “Random signal generator using quantum noise” (2013), which is related to the methods described in ref. 59. M.C. is a named inventor on patents and pending patents related to the methods described in refs 57 and 58. K.T. declares no competing financial interests other than his employment with NTT, Basic Research Lab.

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Lo, HK., Curty, M. & Tamaki, K. Secure quantum key distribution. Nature Photon 8, 595–604 (2014). https://doi.org/10.1038/nphoton.2014.149

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