Abstract
We establish an analytical lower bound on the asymptotic secret key rate of continuous-variable quantum key distribution with an arbitrary modulation of coherent states. Previously, such bounds were only available for protocols with a Gaussian modulation, and numerical bounds existed in the case of simple phase-shift-keying modulations. The latter bounds were obtained as a solution of convex optimization problems and our new analytical bound matches the results of Ghorai et al. (2019), up to numerical precision. The more relevant case of quadrature amplitude modulation (QAM) could not be analyzed with the previous techniques, due to their large number of coherent states. Our bound shows that relatively small constellation sizes, with say 64 states, are essentially sufficient to obtain a performance close to a true Gaussian modulation and are therefore an attractive solution for large-scale deployment of continuous-variable quantum key distribution. We also derive similar bounds when the modulation consists of arbitrary states, not necessarily pure.
Funder
European Union Horizon 2020 Research and Innovation Programme
European Research Council
Publisher
Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften
Subject
Physics and Astronomy (miscellaneous),Atomic and Molecular Physics, and Optics
Reference47 articles.
1. C.H. Bennett and G. Brassard. Quantum cryptography: Public key distribution and coin tossing. In Proceedings of IEEE International Conference on Computers, Systems and Signal Processing, volume 175, 1984. 10.1016/j.tcs.2014.05.025.
2. Kamil Brádler and Christian Weedbrook. Security proof of continuous-variable quantum key distribution using three coherent states. Phys. Rev. A, 97 (2): 022310, 2018. 10.1103/PhysRevA.97.022310.
3. Nicolas J Cerf, Marc Levy, and Gilles Van Assche. Quantum distribution of Gaussian keys using squeezed states. Phys. Rev. A, 63 (5): 052311, 2001. 10.1103/PhysRevA.63.052311.
4. Matthias Christandl, Robert König, and Renato Renner. Postselection technique for quantum channels with applications to quantum cryptography. Phys. Rev. Lett., 102 (2): 020504, 2009. 10.1103/PhysRevLett.102.020504.
5. Aurélie Denys, Peter Brown, and Anthony Leverrier. Explicit asymptotic secret key rate of continuous-variable quantum key distribution with an arbitrary modulation of coherent states. arXiv preprint arXiv:2011.09746v1, 2021.
Cited by
49 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献