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Long-distance device-independent conference key agreement

Makoto Ishihara1,*, Anders J. E. Bjerrum2, Wojciech Roga1, Jonatan B. Brask2, Ulrik L. Andersen2, and Masahiro Takeoka1,3

  • *Contact author: llmakomako.arg1076@keio.jp
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Phys. Rev. A 112, 032429 – Published 19 September, 2025

DOI: https://doi.org/10.1103/2qyl-3rk1

Abstract

Device-independent quantum key distribution (DI-QKD) enables two remote parties to share an information-theoretically secure key without any assumptions on the inner workings of the devices used. Device-independent conference key agreement (DI-CKA) is multipartite DI-QKD in which more than two parties share a common secure key. The performance of DI-CKA, however, is strictly limited because of its susceptibility to losses due to, e.g., imperfect detection efficiency and channel transmission. Here, we propose a DI-CKA protocol which reduces this limitation by using a heralding scheme to distribute multipartite entanglement. We analyze key rates of our protocol for two different measurement scenarios, and we show that our protocol outperforms a previous DI-CKA protocol even with an experimentally feasible measurement.

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References (39)

  1. C. H. Bennett and G. Brassard, Quantum cryptography: Public key distribution and coin tossing, Theor. Comput. Sci. 560, 7 (2014).
  2. A. K. Ekert, Quantum cryptography based on Bell's theorem, Phys. Rev. Lett. 67, 661 (1991).
  3. F. Xu, X. Ma, Q. Zhang, H.-K. Lo, and J.-W. Pan, Secure quantum key distribution with realistic devices, Rev. Mod. Phys. 92, 025002 (2020).
  4. S. Pirandola, U. L. Andersen, L. Banchi, M. Berta, D. Bunandar, R. Colbeck, D. Englund, T. Gehring, C. Lupo, C. Ottaviani, J. L. Pereira, M. Razavi, J. S. Shaari, M. Tomamichel, V. C. Usenko, G. Vallone, P. Villoresi, and P. Wallden, Advances in quantum cryptography, Adv. Opt. Photonics 12, 1012 (2020).
  5. A. Acín, N. Brunner, N. Gisin, S. Massar, S. Pironio, and V. Scarani, Device-independent security of quantum cryptography against collective attacks, Phys. Rev. Lett. 98, 230501 (2007).
  6. S. Pironio, A. Acín, N. Brunner, N. Gisin, S. Massar, and V. Scarani, Device-independent quantum key distribution secure against collective attacks, New J. Phys. 11, 045021 (2009).
  7. V. Zapatero, T. van Leent, R. Arnon-Friedman, W.-Z. Liu, Q. Zhang, H. Weinfurter, and M. Curty, Advances in device-independent quantum key distribution, npj Quantum Inf. 9, 10 (2023).
  8. I. W. Primaatmaja, K. T. Goh, E. Y.-Z. Tan, J. T.-F. Khoo, S. Ghorai, and C. Lim, Security of device-independent quantum key distribution protocols: A review, Quantum 7, 932 (2023).
  9. D. P. Nadlinger, P. Drmota, B. C. Nichol, G. Araneda, D. Main, R. Srinivas, D. M. Lucas, C. J. Ballance, K. Ivanov, E. Y.-Z. Tan, P. Sekatski, R. L. Urbanke, R. Renner, N. Sangouard, and J.-D. Bancal, Experimental quantum key distribution certified by Bell's theorem, Nature (London) 607, 682 (2022).
  10. W. Zhang, T. van Leent, K. Redeker, R. Garthoff, R. Schwonnek, F. Fertig, S. Eppelt, W. Rosenfeld, V. Scarani, C. C.-W. Lim, and H. Weinfurter, A device-independent quantum key distribution system for distant users, Nature (London) 607, 687 (2022).
  11. W.-Z. Liu, Y.-Z. Zhang, Y.-Z. Zhen, M.-H. Li, Y. Liu, J. Fan, F. Xu, Q. Zhang, and J.-W. Pan, Toward a photonic demonstration of device-independent quantum key distribution, Phys. Rev. Lett. 129, 050502 (2022).
  12. J. Ribeiro, G. Murta, and S. Wehner, Fully device-independent conference key agreement, Phys. Rev. A 97, 022307 (2018).
  13. T. Holz, D. Miller, H. Kampermann, and D. Bruß, Comment on “Fully device-independent conference key agreement,” Phys. Rev. A 100, 026301 (2019).
  14. J. Ribeiro, G. Murta, and S. Wehner, Reply to “Comment on ‘Fully device-independent conference key agreement,’” Phys. Rev. A 100, 026302 (2019).
  15. T. Holz, H. Kampermann, and D. Bruß, Genuime multipartite Bell inequality for device-independent conference key agreement, Phys. Rev. Res. 2, 023251 (2020).
  16. F. Grasselli, G. Murta, H. Kampermann, and D. Bruß, Boosting device-independent cryptography with tripartite nonlocality, Quantum 7, 980 (2023).
  17. H. Shimizu, W. Roga, D. Elkouss, and M. Takeoka, Simple loss-tolerant protocol for Greenberger-Horne-Zeilinger-state distribution in a quantum network, Phys. Rev. A 111, 022624 (2025).
  18. N. Gisin, S. Pironio, and N. Sangouard, Proposal for implementing device-independent quantum key distribution based on a heralded qubit amplifier, Phys. Rev. Lett. 105, 070501 (2010).
  19. V. Zapatero and M. Curty, Long-distance device-independent quantum key distribution, Sci. Rep. 9, 17749 (2019).
  20. J. Kołodyński, A. Mátter, P. Skrzypczyk, E. Woodhead, D. Cavalcanti, K. Banaszek, and A. Acín, Device-independent quantum key distribution with single-photon sources, Quantum 4, 260 (2020).
  21. S. Ashhab, K. Maruyama, and F. Nori, Detecting mode entanglement: The role of coherent states, superselection rules and particle statistics, Phys. Rev. A 76, 052113 (2007).
  22. M. Takeoka, M. Sasaki, P. van Loock, and N. Lütkenhaus, Implementation of projective measurements with linear optics and continuous photon counting, Phys. Rev. A 71, 022318 (2005).
  23. M. Takeoka, M. Sasaki, and N. Lütkenhaus, Binary projective measurement via linear optics and photon counting, Phys. Rev. Lett. 97, 040502 (2006).
  24. M. Navascués, S. Pironio, and A. Acín, A convergent hierarchy of semidefinite programs characterizing the set of quantum correlations, New J. Phys. 10, 073013 (2008).
  25. L. Masanes, S. Pironio, and A. Acín, Secure device-independent quantum key distribution with causally independent measurement devices, Nat. Commun. 2, 238 (2011).
  26. O. Nieto-Silleras, S. Pironio, and J. Silman, Using complete measurement statistics for optimal device-independent randomness evaluation, New J. Phys. 16, 013035 (2014).
  27. J.-D. Bancal, L. Sheridan, and V. Scarani, More randomness from the same data, New J. Phys. 16, 033011 (2014).
  28. P. Brown, H. Fawzi, and O. Fawzi, Device-independent lower bounds on the conditional von Neumann entropy, Quantum 8, 1445 (2024).
  29. J. F. Clauser, M. A. Horne, A. Shimony, and R. A. Holt, Proposed experiment to test local hidden-variable theories, Phys. Rev. Lett. 23, 880 (1969).
  30. P. Wittek, Algorithm 950: Ncpol2sdpa-sparse semidefinite programming relaxations for polynomial optimization problems of noncommuting variables, ACM Trans. Math. Software 41, 1 (2015).
  31. M. ApS, MOSEK optimizer API for python 10.2.8 (2024), https://docs.mosek.com/10.2/pythonapi/index.html.
  32. M. Ishihara, LongDistanceDICKA, GitHub (2025), https://github.com/MakotoIshihara/LongDistanceDICKA.
  33. D. V. Reddy, R. R. Nerem, S. W. Nam, R. P. Mirin, and V. B. Verma, Superconducting nanowire single-photon detectors with 98% system detection efficiency at 1550 nm, Optica 7, 1649 (2020).
  34. J. Chang, J. W. N. Los, J. O. Tenorio-Pearl, N. Noordzij, R. Gourgues, A. Guardiani, J. R. Zichi, S. F. Pereira, H. P. Urbach, V. Zwiller, S. N. Dorenbos, and I. E. Zadeh, Detecting telecom single photons with (99.5−2.07+0.5)% system detection efficiency and high time resolution, APL Photonics 6, 036114 (2021).
  35. X. Ma and N. Lütkenhaus, Improved data post-processing in quantum key distribution and application to loss thresholds in device independent QKD, Quantum Inf. Comput. 12, 203 (2012).
  36. E. Y.-Z. Tan, C. C.-W. Lim, and R. Renner, Advantage distillation for device-independent quantum key distribution, Phys. Rev. Lett. 124, 020502 (2020).
  37. M. Ho, P. Sekatski, E. Y.-Z. Tan, R. Renner, J.-D. Bancal, and N. Sangouard, Noisy preprocessing facilitates a photonic realization of device-independent quantum key distribution, Phys. Rev. Lett. 124, 230502 (2020).
  38. F. Xu, Y.-Z. Zhang, Q. Zhang, and J.-W. Pan, Device-independent quantum key distribution with random postselection, Phys. Rev. Lett. 128, 110506 (2022).
  39. L. Wooltorton, P. Brown, and R. Colbeck, Bipartite entanglement is sufficient for standard device-independent conference key agreement, arXiv:2503.21290.

Outline

Information

Phys. Rev. A 112, 032429– Published 19 September, 2025
  • Received 2 June 2025
  • Accepted 5 August 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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