Security Loophole Induced by Photorefractive Effect in Continous-variable Quantum Key Distribution System

Fuente: arXiv
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Main Authors: Zhou, Zehao, Huang, Peng, Wang, Tao, Zeng, Guihua
Format: Preprint
Published: 2024
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author Zhou, Zehao
Huang, Peng
Wang, Tao
Zeng, Guihua
author_facet Zhou, Zehao
Huang, Peng
Wang, Tao
Zeng, Guihua
contents Modulators based on the Mach-Zehnder interferometer (MZI) structure are widely used in continuous-variable quantum key distribution (CVQKD) systems. MZI-based variable optical attenuator (VOA) and amplitude modulator can reshape the waveform and control the intensity of coherent state signal to realize secret key information modulation in CVQKD system. However, these devices are not ideal, internal and external effects like non-linear effect and temperature may degrade their performance. In this paper, we analyzed the security loophole of CVQKD under the photorefractive effect (PE), which originates from the crystal characteristic of lithium niobate (LN). It is found that the refractive index change of modulators because of PE may lead to an overestimate or underestimate of the final secret key rate. This allows Eve to perform further attacks like intercept-resend to get more secret key information. To solve this problem, several countermeasures are proposed, which can effectively eliminate potential risks.
format Preprint
id arxiv_https___arxiv_org_abs_2409_00497
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Security Loophole Induced by Photorefractive Effect in Continous-variable Quantum Key Distribution System
Zhou, Zehao
Huang, Peng
Wang, Tao
Zeng, Guihua
Quantum Physics
Cryptography and Security
Modulators based on the Mach-Zehnder interferometer (MZI) structure are widely used in continuous-variable quantum key distribution (CVQKD) systems. MZI-based variable optical attenuator (VOA) and amplitude modulator can reshape the waveform and control the intensity of coherent state signal to realize secret key information modulation in CVQKD system. However, these devices are not ideal, internal and external effects like non-linear effect and temperature may degrade their performance. In this paper, we analyzed the security loophole of CVQKD under the photorefractive effect (PE), which originates from the crystal characteristic of lithium niobate (LN). It is found that the refractive index change of modulators because of PE may lead to an overestimate or underestimate of the final secret key rate. This allows Eve to perform further attacks like intercept-resend to get more secret key information. To solve this problem, several countermeasures are proposed, which can effectively eliminate potential risks.
title Security Loophole Induced by Photorefractive Effect in Continous-variable Quantum Key Distribution System
topic Quantum Physics
Cryptography and Security
url https://arxiv.org/abs/2409.00497