Composable free-space continuous-variable quantum key distribution using discrete modulation

Fuente: arXiv
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Main Authors: Jaksch, Kevin, Dirmeier, Thomas, Weiser, Yannick, Richter, Stefan, Bayraktar, Ömer, Hacker, Bastian, Rösler, Conrad, Khan, Imran, Petscharning, Stefan, Grafenauer, Thomas, Hentschel, Michael, Ömer, Bernhard, Pacher, Christoph, Kanitschar, Florian, Upadhyaya, Twesh, Lin, Jie, Lütkenhaus, Norbert, Leuchs, Gerd, Marquardt, Christoph
Format: Preprint
Published: 2024
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author Jaksch, Kevin
Dirmeier, Thomas
Weiser, Yannick
Richter, Stefan
Bayraktar, Ömer
Hacker, Bastian
Rösler, Conrad
Khan, Imran
Petscharning, Stefan
Grafenauer, Thomas
Hentschel, Michael
Ömer, Bernhard
Pacher, Christoph
Kanitschar, Florian
Upadhyaya, Twesh
Lin, Jie
Lütkenhaus, Norbert
Leuchs, Gerd
Marquardt, Christoph
author_facet Jaksch, Kevin
Dirmeier, Thomas
Weiser, Yannick
Richter, Stefan
Bayraktar, Ömer
Hacker, Bastian
Rösler, Conrad
Khan, Imran
Petscharning, Stefan
Grafenauer, Thomas
Hentschel, Michael
Ömer, Bernhard
Pacher, Christoph
Kanitschar, Florian
Upadhyaya, Twesh
Lin, Jie
Lütkenhaus, Norbert
Leuchs, Gerd
Marquardt, Christoph
contents Continuous-variable (CV) quantum key distribution (QKD) allows for quantum secure communication with the benefit of being close to existing classical coherent communication. In recent years, CV QKD protocols using a discrete number of displaced coherent states have been studied intensively, as the modulation can be directly implemented with real devices with a finite digital resolution. However, the experimental demonstrations until now only calculated key rates in the asymptotic regime. To be used in cryptographic applications, a QKD system has to generate keys with composable security in the finite-size regime. In this paper, we present a CV QKD system using discrete modulation that is especially designed for urban atmospheric channels. For this, we use polarization encoding to cope with the turbulent but non-birefringent atmosphere. This will allow to expand CV QKD networks beyond the existing fiber backbone. In a first laboratory demonstration, we implemented a novel type of security proof allowing to calculate composable finite-size key rates against i.i.d. collective attacks without any Gaussian assumptions. We applied the full QKD protocol including a QRNG, error correction and privacy amplification to extract secret keys. In particular, we studied the impact of frame errors on the actual key generation.
format Preprint
id arxiv_https___arxiv_org_abs_2410_12915
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Composable free-space continuous-variable quantum key distribution using discrete modulation
Jaksch, Kevin
Dirmeier, Thomas
Weiser, Yannick
Richter, Stefan
Bayraktar, Ömer
Hacker, Bastian
Rösler, Conrad
Khan, Imran
Petscharning, Stefan
Grafenauer, Thomas
Hentschel, Michael
Ömer, Bernhard
Pacher, Christoph
Kanitschar, Florian
Upadhyaya, Twesh
Lin, Jie
Lütkenhaus, Norbert
Leuchs, Gerd
Marquardt, Christoph
Quantum Physics
Continuous-variable (CV) quantum key distribution (QKD) allows for quantum secure communication with the benefit of being close to existing classical coherent communication. In recent years, CV QKD protocols using a discrete number of displaced coherent states have been studied intensively, as the modulation can be directly implemented with real devices with a finite digital resolution. However, the experimental demonstrations until now only calculated key rates in the asymptotic regime. To be used in cryptographic applications, a QKD system has to generate keys with composable security in the finite-size regime. In this paper, we present a CV QKD system using discrete modulation that is especially designed for urban atmospheric channels. For this, we use polarization encoding to cope with the turbulent but non-birefringent atmosphere. This will allow to expand CV QKD networks beyond the existing fiber backbone. In a first laboratory demonstration, we implemented a novel type of security proof allowing to calculate composable finite-size key rates against i.i.d. collective attacks without any Gaussian assumptions. We applied the full QKD protocol including a QRNG, error correction and privacy amplification to extract secret keys. In particular, we studied the impact of frame errors on the actual key generation.
title Composable free-space continuous-variable quantum key distribution using discrete modulation
topic Quantum Physics
url https://arxiv.org/abs/2410.12915