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  • Review Article
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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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References

  1. Rivest, R. L., Shamir, A. & Adleman, L. M. A method of obtaining digital signatures and public-key cryptosystems. Commun. ACM 21, 120–126 (1978).

    Article  MathSciNet  MATH  Google Scholar 

  2. Shor, P. W. Algorithms for quantum computation: discrete logarithms and factoring. in Proc. 35th Ann. Symp. Found. Comp. Sci. (ed. Goldwasser, S.) 124–134 (IEEE, 1994).

    Chapter  Google Scholar 

  3. Ben-Or, M., Horodecki, M., Leung, D. W., Mayers, D. & Oppenheim, J. The universal composable security of quantum key distribution. in Theory of Cryptography (ed. Kilian, J.) 3378, 386–406 (Springer, 2005).

    Chapter  MATH  Google Scholar 

  4. Renner, R. & König, R. Universally composable privacy amplification against quantum adversaries. in Theory of Cryptography (ed. Kilian, J.) 3378, 407–425 (Springer, 2005).

    Chapter  Google Scholar 

  5. Yoshino, K., Ochi, T., Fujiwara, M., Sasaki, M. & Tajima, A. Maintenance-free operation of WDM quantum key distribution system through a field fiber over 30 days. Opt. Express 21, 31395–31401 (2013).

    Article  ADS  Google Scholar 

  6. Ursin, R. et al. Entanglement-based quantum communication over 144 km. Nature Phys. 3, 481–486 (2007).

    Article  ADS  Google Scholar 

  7. Elliott, C. et al. Current status of the DARPA Quantum Network. in Proc. SPIE (eds Donkor, E. J., Pirich, A. R. & Brandt, H. E.) 5815, 138–149 (SPIE, 2005).

    Google Scholar 

  8. Peev, M. et al. The SECOQC quantum key distribution network in Vienna. New J. Phys. 11, 075001 (2009).

    Article  ADS  Google Scholar 

  9. Stucki, D. et al. Long-term performance of the SwissQuantum quantum key distribution network in a field environment. New J. Phys. 13, 123001 (2011).

    Article  ADS  Google Scholar 

  10. Chen, T.-Y. et al. Field test of a practical secure communication network with decoy-state quantum cryptography. Opt. Express 17, 6540–6549 (2009).

    Article  ADS  Google Scholar 

  11. Chen, T.-Y. et al. Metropolitan all-pass and inter-city quantum communication network. Opt. Express 18, 27217–27225 (2010).

    Article  ADS  Google Scholar 

  12. Wang, S. et al. Field test of wavelength-saving quantum key distribution network. Opt. Lett. 35, 2454–2456 (2010).

    Article  ADS  Google Scholar 

  13. Sasaki, M. et al. Field test of quantum key distribution in the Tokyo QKD network. Opt. Express 19, 10387–10409 (2011).

    Article  ADS  Google Scholar 

  14. Fröhlich, B. et al. A quantum access network. Nature 501, 69–72 (2013).

    Article  ADS  Google Scholar 

  15. Marsili, F. et al. Detecting single infrared photons with 93% system efficiency. Nature Photon. 7, 210–214 (2013).

    Article  ADS  Google Scholar 

  16. Rosenberg, D., Kerman, A. J., Molnar, R. J. & Dauler, E. A. High-speed and high-efficiency superconducting nanowire single photon detector array. Opt. Express 21, 1440–1447 (2013).

    Article  ADS  Google Scholar 

  17. Miki, S., Yamashita, T., Terai, H. & Wang, Z. High performance fiber-coupled NbTiN superconducting nanowire single photon detectors with Gifford-McMahon cryocooler. Opt. Express 21, 10208–10214 (2013).

    Article  ADS  Google Scholar 

  18. Restelli, A., Bienfang, J. C. & Migdall, A. L. Single-photon detection efficiency up to 50% at 1310 nm with an InGaAs/InP avalanche diode gated at 1.25 GHz. Appl. Phys. Lett. 102, 141104 (2013).

    Article  ADS  Google Scholar 

  19. Bennett, C. H., Bessette, F., Brassard, G., Salvail, L. & Smolin, J. Experimental quantum cryptography. J. Cryptol. 5, 3–28 (1992).

    Article  MATH  Google Scholar 

  20. Wang, J.-Y. et al. Direct and full-scale experimental verifications towards ground-satellite quantum key distribution. Nature Photon. 7, 387–393 (2013).

    Article  ADS  Google Scholar 

  21. Nauerth, S. et al. Air-to-ground quantum communication. Nature Photon. 7, 382–386 (2013).

    Article  ADS  Google Scholar 

  22. Lim, C. C. W., Curty, M., Walenta, N., Xu, F. & Zbinden, H. Concise security bounds for practical decoy-state quantum key distribution. Phys. Rev. A 89, 022307 (2014).

    Article  ADS  Google Scholar 

  23. Bennett, C. H. & Brassard, G. Quantum cryptography: public key distribution and coin tossing. in Proc. IEEE Int. Conf. Comp. Systems Signal Processing 175–179 (IEEE, 1984).

    Google Scholar 

  24. Huttner, B., Imoto, N., Gisin, N. & Mor, T. Quantum cryptography with coherent states. Phys. Rev. A 51, 1863–1869 (1995).

    Article  ADS  Google Scholar 

  25. Gottesman, D., Lo, H.-K., Lütkenhaus, N. & Preskill, J. Security of quantum key distribution with imperfect devices. Quant. Inf. Comp. 5, 325–360 (2004).

    MathSciNet  MATH  Google Scholar 

  26. Hwang, W.-Y. Quantum key distribution with high loss: toward global secure communication. Phys. Rev. Lett. 91, 057901 (2003).

    Article  ADS  Google Scholar 

  27. Lo, H.-K., Ma, X. & Chen, K. Decoy state quantum key distribution. Phys. Rev. Lett. 94, 230504 (2005).

    Article  ADS  Google Scholar 

  28. Wang, X.-B. Beating the photon-number-splitting attack in practical quantum cryptography. Phys. Rev. Lett. 94, 230503 (2005).

    Article  ADS  Google Scholar 

  29. Ma, X., Qi, B., Zhao, Y. & Lo, H.-K. Practical decoy state for quantum key distribution. Phys. Rev. A 72, 012326 (2005).

    Article  ADS  Google Scholar 

  30. Zhao, Y., Qi, B., Ma, X., Lo, H.-K. & Qian, L. Experimental quantum key distribution with decoy states. Phys. Rev. Lett. 96, 070502 (2006).

    Article  ADS  Google Scholar 

  31. Peng, C.-Z. et al. Experimental long-distance decoy-state quantum key distribution based on polarization encoding. Phys. Rev. Lett. 98, 010505 (2007).

    Article  ADS  Google Scholar 

  32. Rosenberg, D. et al. Long-distance decoy-state quantum key distribution in optical fiber. Phys. Rev. Lett. 98, 010503 (2007).

    Article  ADS  Google Scholar 

  33. Schmitt-Manderbach, T. et al. Experimental demonstration of free-space decoy-state quantum key distribution over 144 km. Phys. Rev. Lett. 98, 010504 (2007).

    Article  ADS  Google Scholar 

  34. Yuan, Z. L., Sharpe, A. W. & Shields, A. J. Unconditionally secure one-way quantum key distribution using decoy pulses. Appl. Phys. Lett. 90, 011118 (2007).

    Article  ADS  Google Scholar 

  35. Liu, Y. et al. Decoy-state quantum key distribution with polarized photons over 200 km. Opt. Express 18, 8587–8594 (2010).

    Article  ADS  Google Scholar 

  36. Wehner, S., Curty, M., Schaffner, C. & Lo, H.-K. Implementation of two-party protocols in the noisy-storage model. Phys. Rev. A 81, 052336 (2010).

    Article  ADS  Google Scholar 

  37. Hughes, R. J. et al. Network-centric quantum communications with application to critical infrastructure protection. Preprint at http://lanl.arXiv.org/abs/1305.0305 (2013).

  38. Ekert, A. K. Quantum cryptography based on Bell's theorem. Phys. Rev. Lett. 67, 661–663 (1991).

    Article  ADS  MathSciNet  MATH  Google Scholar 

  39. Ma, X., Fung, C.-H. F. & Lo, H.-K. Quantum key distribution with entangled photon sources. Phys. Rev. A 76, 012307 (2007).

    Article  ADS  Google Scholar 

  40. Treiber, A. et al. Fully automated entanglement-based quantum cryptography system for telecom fiber networks. New J. Phys. 11, 045013 (2009).

    Article  ADS  Google Scholar 

  41. Poppe, A. et al. Practical quantum key distribution with polarization-entangled photons. Opt. Express 12, 3865–3871 (2004).

    Article  ADS  Google Scholar 

  42. Inoue, K., Waks, E. & Yamamoto, Y. Differential phase shift quantum key distribution. Phys. Rev. Lett. 89, 037902 (2002).

    Article  ADS  Google Scholar 

  43. Takesue, H. et al. Quantum key distribution over a 40-dB channel loss using superconducting single-photon detectors. Nature Photon. 1, 343–348 (2007).

    Article  ADS  Google Scholar 

  44. Stucki, D. et al. High rate, long-distance quantum key distribution over 250 km of ultra low loss fibres. New J. Phys. 11, 075003 (2009).

    Article  ADS  Google Scholar 

  45. Grosshans, F. et al. Quantum key distribution using gaussian-modulated coherent states. Nature 421, 238–241 (2003).

    Article  ADS  Google Scholar 

  46. Qi, B., Huang, L.-L., Qian, L. & Lo, H.-K. Experimental study on the Gaussian-modulated coherent-state quantum key distribution over standard telecommunication fibers. Phys. Rev. A 76, 052323 (2007).

    Article  ADS  Google Scholar 

  47. Jouguet, P., Kunz-Jacques, S., Leverrier, A., Grangier, P. & Diamanti, E. Experimental demonstration of long-distance continuous-variable quantum key distribution. Nature Photon. 7, 378–381 (2013).

    Article  ADS  Google Scholar 

  48. Yuan, Z. L., Kardynal, B. E., Sharpe, A. W. & Shields, A. J. High speed single photon detection in the near infrared. App. Phys. Lett. 91, 041114 (2007).

    Article  ADS  Google Scholar 

  49. Dixon, A. R. et al. Ultrashort dead time of photon-counting InGaAs avalanche photodiodes. Appl. Phys. Lett. 94, 231113 (2009).

    Article  ADS  Google Scholar 

  50. Namekata, N., Sasamori, S. & Inoue, S. 800 MHz single-photon detection at 1550-nm using an InGaAs/InP avalanche photodiode operated with a sine wave gating. Opt. Express 14, 10043–10049 (2006).

    Article  ADS  Google Scholar 

  51. Liang, X.-L. et al. Fully integrated InGaAs/InP single-photon detector module with gigahertz sine wave gating. Rev. Sci. Instrum. 83, 083111 (2012).

    Article  ADS  Google Scholar 

  52. Wu, Q.-L., Namekata, N. & Inoue, S. Sinusoidally gated InGaAs avalanche photodiode with direct hold-off function for efficient and low-noise single-photon detection. Appl. Phys. Express 6, 062202 (2013).

    Article  ADS  Google Scholar 

  53. Zhang, J., Thew, R., Barreiro, C. & Zbinden, H. Practical fast gate rate InGaAs/InP single-photon avalanche photodiodes. Appl. Phys. Lett. 95, 091103 (2009).

    Article  ADS  Google Scholar 

  54. Shibata, H., Takesue, H., Honjo, T., Akazaki, T. & Tokura, Y. Single-photon detection using magnesium diboride superconducting nanowires. Appl. Phys. Lett. 97, 212504 (2010).

    Article  ADS  Google Scholar 

  55. Pironio, S. et al. Random numbers certified by Bell's theorem. Nature 464, 1021–1024 (2010).

    Article  ADS  Google Scholar 

  56. Williams, C. R. S., Salevan, J. C., Li, X., Roy, R. & Murphy, T. E. Fast physical random number generator using amplified spontaneous emission. Opt. Express 18, 23584–23597 (2010).

    Article  ADS  Google Scholar 

  57. Jofre, M. et al. True random numbers from amplified quantum vacuum. Opt. Express 19, 20665–20672 (2011).

    Article  ADS  Google Scholar 

  58. Abellán, C. et al. Ultra-fast quantum randomness generation by accelerated phase diffusion in a pulsed laser diode. Opt. Express 22, 1645–1654 (2014).

    Article  ADS  Google Scholar 

  59. Qi, B., Chi, Y.-M., Lo, H.-K. & Qian, L. High-speed quantum random number generation by measuring phase noise of a single-mode laser. Opt. Lett. 35, 312–314 (2010).

    Article  ADS  Google Scholar 

  60. Dixon, A. R., Yuan, Z. L., Dynes, J. F., Sharpe, A. W. & Shields, A. J. Continuous operation of high bit rate quantum key distribution. Appl. Phys. Lett. 96, 161102 (2010).

    Article  ADS  Google Scholar 

  61. Choi, I., Young, R. J. & Townsend, P. D. Quantum key distribution on a 10Gb/s WDM-PON. Opt. Express 18, 9600–9612 (2010).

    Article  ADS  Google Scholar 

  62. Patel, K. A. et al. Coexistence of high-bit-rate quantum key distribution and data on optical fiber. Phys. Rev. X 2, 041010 (2012).

    Google Scholar 

  63. Chapuran, T. E. et al. Optical networking for quantum key distribution and quantum communications. New J. Phys. 11, 105001 (2009).

    Article  ADS  Google Scholar 

  64. Patel, K. A. et al. Quantum key distribution for 10 Gb/s dense wavelength division multiplexing networks. Appl. Phys. Lett. 104, 051123 (2014).

    Article  ADS  Google Scholar 

  65. Dixon, A. R., Yuan, Z. L., Dynes, J. F., Sharpe, A. W. & Shields, A. J. Gigahertz decoy quantum key distribution with 1 Mbit/s secure key rate. Opt. Express 16, 18790–18979 (2008).

    Article  ADS  Google Scholar 

  66. Zhang, Q. et al. Megabits secure key rate quantum key distribution. New J. Phys. 11, 045010 (2009).

    Article  ADS  Google Scholar 

  67. Tanaka, A. et al. High-speed quantum key distribution system for 1-Mbps real-time key generation. IEEE J. Quant. Electron. 48, 542–550 (2012).

    Article  ADS  Google Scholar 

  68. Walenta, N. et al. 1 Mbps coherent one-way QKD with dense wavelength division multiplexing and hardware key distillation. in Proc. 2nd Ann. Conf. Quantum Cryptography (2012).

    Google Scholar 

  69. Qi, B., Zhu, W., Qian, L. & Lo, H.-K. Feasibility of quantum key distribution through dense wavelength division multiplexing network. New J. Phys. 12, 103042 (2010).

    Article  ADS  Google Scholar 

  70. Jouguet, P. et al. Experimental demonstration of the coexistence of continuous-variable quantum key distribution with an intense DWDM classical channel. in Proc. 3rd Ann. Conf. Quantum Cryptography (2013).

    Google Scholar 

  71. Raymer, M. G., Cooper, J., Carmichael, H. J., Beck M. & Smithey, D. T. Ultrafast measurement of optical-field statistics by dc-balanced homodyne detection. J. Opt. Soc. Am. B 12, 1801–1812 (1995).

    Article  ADS  Google Scholar 

  72. Hayashi, M. & Tsurumaru, T. Concise and tight security analysis of the Bennett–Brassard 1984 protocol with finite key lengths. New J. Phys. 14, 093014 (2012).

    Article  ADS  Google Scholar 

  73. Curty, M. et al. Finite-key analysis for measurement-device-independent quantum key distribution. Nature Commun. 5, 3732 (2014).

    Article  ADS  Google Scholar 

  74. Lo, H.-K., Curty, M. & Qi, B. Measurement-device-independent quantum key distribution. Phys. Rev. Lett. 108, 130503 (2012).

    Article  ADS  Google Scholar 

  75. Qi, B., Fung, C.-H. F., Lo, H.-K. & Ma, X. Time-shift attack in practical quantum cryptosystems. Quant. Inf. Comp. 7, 73–82 (2007).

    MathSciNet  MATH  Google Scholar 

  76. Zhao, Y., Fung, C.-H. F., Qi, B., Chen, C. & Lo, H.-K. Quantum hacking: experimental demonstration of time-shift attack against practical quantum-key-distribution systems. Phys. Rev. A 78, 042333 (2008).

    Article  ADS  Google Scholar 

  77. Makarov, V., Anisimov, A. & Skaar, J. Effects of detector efficiency mismatch on security of quantum cryptosystems. Phys. Rev. A 74, 022313 (2006).

    Article  ADS  Google Scholar 

  78. Makarov, V., Anisimov, A. & Skaar, J. Erratum: effects of detector efficiency mismatch on security of quantum cryptosystems [Phys. Rev. A 74, 022313 (2006)]. Phys. Rev. A 78, 019905 (2008).

    Article  ADS  Google Scholar 

  79. Lamas-Linares, A. & Kurtsiefer, C. Breaking a quantum key distribution system through a timing side channel. Opt. Express 15, 9388–9393 (2007).

    Article  ADS  Google Scholar 

  80. Lydersen, L. et al. Hacking commercial quantum cryptography systems by tailored bright illumination. Nature Photon. 4, 686–689 (2010).

    Article  ADS  Google Scholar 

  81. Yuan, Z. L., Dynes, J. F. & Shields, A. J. Avoiding the blinding attack in QKD. Nature Photon. 4, 800–801 (2010).

    Article  ADS  Google Scholar 

  82. Lydersen, L. et al. Reply to “Avoiding the blinding attack in QKD”. Nature Photon. 4, 801 (2010).

    Article  ADS  Google Scholar 

  83. Gerhardt, I. et al. Full-field implementation of a perfect eavesdropper on a quantum cryptography system. Nature Commun. 2, 349 (2011).

    Article  ADS  Google Scholar 

  84. Weier, H. et al. Quantum eavesdropping without interception: an attack exploiting the dead time of single-photon detectors. New J. Phys. 13, 073024 (2011).

    Article  ADS  Google Scholar 

  85. Jain, N. et al. Device calibration impacts security of quantum key distribution. Phys. Rev. Lett. 107, 110501 (2011).

    Article  ADS  Google Scholar 

  86. Xu, F., Qi, B. & Lo, H.-K. Experimental demonstration of phase-remapping attack in a practical quantum key distribution system. New J. Phys. 12, 113026 (2010).

    Article  ADS  Google Scholar 

  87. Sun, S.-H., Jiang, M.-S. & Liang, L.-M. Passive Faraday-mirror attack in a practical two-way quantum-key-distribution system. Phys. Rev. A 83, 062331 (2011).

    Article  ADS  Google Scholar 

  88. Huang, J.-Z. et al. Quantum hacking on continuous-variable quantum key distribution system using a wavelength attack. Phys. Rev. A 87, 062329 (2013).

    Article  ADS  Google Scholar 

  89. Tang, Y.-L. et al. Source attack of decoy-state quantum key distribution using phase information. Phys. Rev. A 88, 022308 (2013).

    Article  ADS  Google Scholar 

  90. Jouguet, P., Kunz-Jacques, S. & Diamanti, E. Preventing calibration attacks on the local oscillator in continuous-variable quantum key distribution. Phys. Rev. A 87, 062313 (2013).

    Article  ADS  Google Scholar 

  91. Tamaki, K., Curty, M., Kato, G., Lo, H.-K. & Azuma, K. Loss-tolerant quantum cryptography with imperfect sources. Preprint at http://lanl.arXiv.org/abs/1312.3514 (2013).

  92. Yuan, Z. L., Dynes, J. F. & Shields, A. J. Resilience of gated avalanche photodiodes against bright illumination attacks in quantum cryptography. Appl. Phys. Lett. 98, 231104 (2011).

    Article  ADS  Google Scholar 

  93. Lydersen, L., Makarov, V. & Skaar, J. Comment on “Resilience of gated avalanche photodiodes against bright illumination attacks in quantum cryptography”. Appl. Phys. Lett. 99, 196101 (2011).

    Article  ADS  Google Scholar 

  94. Yuan, Z. L., Dynes, J. F. & Shields, A. J. Response to “Comment on 'Resilience of gated avalanche photodiodes against bright illumination attacks in quantum cryptography”' Appl. Phys. Lett. 99, 196102 (2011).

    Article  ADS  Google Scholar 

  95. Honjo, T. et al. Countermeasure against tailored bright illumination attack for DPS-QKD. Opt. Express 21, 2667–2673 (2013).

    Article  ADS  Google Scholar 

  96. Mayers, D. & Yao, A. Quantum cryptography with imperfect apparatus. in Proc. 39th Ann. Symp. Foundations Comp. Sci. 503–509 (IEEE, 1998).

    Google Scholar 

  97. Masanes, L., Pironio, S. & Acín, A. Secure device-independent quantum key distribution with causally in-dependent measurement devices. Nature Commun. 2, 238 (2011).

    Article  ADS  Google Scholar 

  98. Reichardt, B. W., Unger, F. & Vazirani, U. Classical command of quantum systems. Nature 496, 456–460 (2013).

    Article  ADS  Google Scholar 

  99. Vazirani, U. & Vidick, T. Fully device independent quantum key distribution. Preprint at http://lanl.arXiv.org/abs/1210.1810 (2012).

  100. Gisin, N., Pironio, S. & Sangouard, N. Proposal for implementing device-independent quantum key distribution based on a heralded qubit amplifier. Phys. Rev. Lett. 105, 070501 (2010).

    Article  ADS  Google Scholar 

  101. Curty, M. & Moroder, T. Heralded-qubit amplifiers for practical device-independent quantum key distribution. Phys. Rev. A 84, 10.1103/PhysRevA.84.010304 010304(R)(2011).

    Article  ADS  Google Scholar 

  102. Biham, E., Huttner, B. & Mor, T. Quantum cryptographic network based on quantum memories. Phys. Rev. A 54, 2651–2658 (1996).

    Article  ADS  MathSciNet  Google Scholar 

  103. Inamori, H. Security of practical time-reversed EPR quantum key distribution. Algorithmica 34, 340–365 (2002).

    Article  MathSciNet  MATH  Google Scholar 

  104. Rubenok, A., Slater, J. A., Chan, P., Lucio-Martinez, I. & Tittel, W. Real-world two-photon interference and proof-of-principle quantum key distribution immune to detector attacks. Phys. Rev. Lett. 111, 130501 (2013).

    Article  ADS  Google Scholar 

  105. Ferreira da Silva, T. et al. Proof-of-principle demonstration of measurement-device-independent quantum key distribution using polarization qubits. Phys. Rev. A 88, 052303 (2013).

    Article  ADS  Google Scholar 

  106. Liu, Y. et al. Experimental measurement-device-independent quantum key distribution. Phys. Rev. Lett. 111, 130502 (2013).

    Article  ADS  Google Scholar 

  107. Tang, Z. et al. Experimental demonstration of polarization encoding measurement-device-independent quantum key distribution. Phys. Rev. Lett. 112, 190503 (2014).

    Article  ADS  Google Scholar 

  108. Briegel, H.-J., Dür, W., Cirac, J. I. & Zoller, P. Quantum repeaters: the role of imperfect local operations in quantum communication. Phys. Rev. Lett. 81, 5932–5935 (1998).

    Article  ADS  Google Scholar 

  109. Vernam, G. S. Cipher printing telegraph systems: for secret wire and radio telegraphic communications. J. Am. Inst. Electr. Eng. 45, 109–115 (1926).

    Google Scholar 

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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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