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Experimental quantum key distribution without monitoring signal disturbance

Nature Photonics volume 9, pages 827831 (2015) | Download Citation

Abstract

Quantum key distribution (QKD) is a method of realizing private communication securely against an adversary with unlimited power. The QKD protocols proposed and demonstrated over the past 30 years relied on the monitoring of signal disturbance to set an upper limit to the amount of leaked information. Here, we report an experimental realization of the recently proposed round-robin differential-phase-shift protocol. We used a receiver set-up in which photons are randomly routed to one of four interferometers with different delays so that the phase difference is measured uniformly over all pair combinations among five pulses comprising the quantum signal. The amount of leak can be bounded from this randomness alone, and a secure key was extracted even when a finite communication time and the threshold nature of photon detectors were taken into account. This demonstrates the first QKD experiment without signal disturbance monitoring, thus opening up a new direction towards secure communication.

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References

  1. 1.

    , , & Quantum cryptography. Rev. Mod. Phys. 74, 145–195 (2002).

  2. 2.

    & in Proceedings of IEEE International Conference on Computers, Systems and Signal Processing 175–179 (IEEE Press, 1984).

  3. 3.

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

  4. 4.

    Quantum cryptography using any two nonorthogonal states. Phys. Rev. Lett. 68, 3121–3124 (1992).

  5. 5.

    , , & Quantum cryptography with coherent states. Phys. Rev. A 51, 1863–1869 (1995).

  6. 6.

    , , , & Experimental demonstration of long-distance continuous-variable quantum key distribution. Nature Photon. 14, 378–381 (2013).

  7. 7.

    , & Differential phase shift quantum key distribution. Phys. Rev. Lett. 89, 037902 (2002).

  8. 8.

    , , & Quantum cryptography protocols robust against photon number splitting attacks for weak laser pulse implementations. Phys. Rev. Lett. 92, 057901 (2004).

  9. 9.

    , , , & Fast and simple one-way quantum key distribution. Appl. Phys. Lett. 87, 194108 (2005).

  10. 10.

    , , , & Gigahertz decoy quantum key distribution with 1 Mbit/s secure key rate. Opt. Express 16, 18790–18797 (2008).

  11. 11.

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

  12. 12.

    , , , & Continuous operation of high bit rate quantum key distribution. Appl. Phys. Lett. 96, 161102 (2010).

  13. 13.

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

  14. 14.

    et al. Efficient decoy-state quantum key distribution with quantified security. Opt. Express 21, 24550–24565 (2013).

  15. 15.

    , & Quantum key distribution over 122 km of standard telecom fiber. Appl. Phys. Lett. 84, 3762–3764 (2004).

  16. 16.

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

  17. 17.

    et al. Provably secure and practical quantum key distribution over 307 km of optical fiber. Nature Photon. 9, 163–168 (2015).

  18. 18.

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

  19. 19.

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

  20. 20.

    et al. The security of practical quantum key distribution. Rev. Mod. Phys. 81, 1301–1350 (2009).

  21. 21.

    , & Practical quantum key distribution protocol without monitoring signal disturbance. Nature 509, 475–478 (2014).

  22. 22.

    , & Security of differential-phase-shift quantum key distribution against individual attacks. Phys. Rev. A 73, 012344 (2006).

  23. 23.

    , & Unconditional security of single-photon differential phase shift quantum key distribution. Phys. Rev. Lett. 103, 170503 (2009).

  24. 24.

    , & Unconditional security of coherent-state-based differential phase shift quantum key distribution protocol with block-wise phase randomization. Preprint at (2012).

  25. 25.

    , & Differential-phase-shift quantum key distribution experiment with a planar light-wave circuit Mach–Zehnder interferometer. Opt. Lett. 29, 2797–2799 (2004).

  26. 26.

    & Differential-phase-shift quantum key distribution with an extended degree of freedom. Opt. Lett. 31, 522–524 (2006).

  27. 27.

    et al. Compact optical buffer module for intra-packet synchronization based on InP 1×8 switch and silica-based delay line circuit. IEICE Trans. Electron. E96-C, 738–743 (2013).

  28. 28.

    et al. On-chip detection of non-classical light by scalable integration of single-photon detectors. Nature Commun. 6, 5873 (2015).

  29. 29.

    et al. Low-loss and high-extinction ratio silica-based strictly nonblocking 16×16 thermooptic matrix switch. IEEE Photon. Technol. Lett. 10, 810–812 (1998).

  30. 30.

    , & Decoy state quantum key distribution. Phys. Rev. Lett. 94, 230504 (2005).

  31. 31.

    , , , & 64QAM modulator with a hybrid configuration of silica PLCs and LiNbO3 phase modulators. IEEE Photon. Technol. Lett. 22, 344–346 (2010).

  32. 32.

    , , & Security of quantum key distribution with imperfect device. Quant. Inf. Comp. 4, 325–360 (2004).

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Acknowledgements

The authors thank Y. Yamamoto, T. Yamada and M. Oguma for discussions. This work was funded in part by the ImPACT Program of the Council for Science, Technology and Innovation (Cabinet Office, Government of Japan) and the Photon Frontier Network Program (MEXT).

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Affiliations

  1. NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan

    • Hiroki Takesue
    •  & Kiyoshi Tamaki
  2. Photon Science Center, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan

    • Toshihiko Sasaki
    •  & Masato Koashi

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Contributions

H.T. designed and constructed the experimental set-up and performed the QKD experiments. T.S. and M.K. designed the detailed procedure for secure key generation. H.T., T.S. and K.T. undertook the data analysis. M.K. led the project. All authors discussed the results and wrote the paper.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Hiroki Takesue or Toshihiko Sasaki.

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DOI

https://doi.org/10.1038/nphoton.2015.173

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