English
Related papers

Related papers: Improvement of continuous-variable quantum key dis…

200 papers

In a practical CVQKD system, the optical attenuator can adjust the Gaussian-modulated coherent states and the local oscillator signal to an optimal value for guaranteeing the security of the system and optimizing the performance of the…

Quantum Physics · Physics 2019-07-17 Yi Zheng , Peng Huang , Anqi Huang , Jinye Peng , Guihua Zeng

Quantum key distribution provides secure keys with information-theoretic security ensured by the principle of quantum mechanics. The continuous-variable version of quantum key distribution using coherent states offers the advantages of its…

Quantum Physics · Physics 2024-07-09 Yichen Zhang , Yiming Bian , Zhengyu Li , Song Yu , Hong Guo

Continuous-variable quantum key distribution (CV-QKD) enables information-theoretically secure key generation between legitimate parties. To further enhance system performance, an improved two-way CV-QKD protocol has been proposed, which is…

Quantum Physics · Physics 2026-01-28 Yanhao Sun , Jiayu Ma , Xiangyu Wang , Song Yu , Ziyang Chen , Hong Guo

We investigate the main limitations which prevent the continuous-variable quantum key distribution protocols from achieving long distances in the finite-size setting. We propose a double-modulation protocol which allows using each state for…

Quantum Physics · Physics 2014-12-22 László Ruppert , Vladyslav C. Usenko , Radim Filip

We have improved the hardware and software of our autocompensating system for quantum key distribution by replacing bulk optical components at the end stations with fiber-optic equivalents and implementing software that synchronizes…

Quantum Physics · Physics 2009-11-07 Donald S. Bethune , Martha Navarro , William P. Risk

Most continuous-variable quantum key distribution schemes are based on the Gaussian modulation of coherent states followed by continuous quadrature detection using homodyne detectors. In all previous schemes, the Gaussian modulation has…

Quantum Physics · Physics 2016-09-06 Tobias Gehring , Christian S. Jacobsen , Ulrik L. Andersen

We propose a continuous variable quantum key distribution protocol based on discrete modulation of eight-state coherent states. We present a rigorous security proof against the collective attacks considering both of realistic lossy, noisy…

Quantum Physics · Physics 2010-06-23 A. Becir , F. A. A. El-Orany , M. R. B. Wahiddin

Phase-insensitive optical amplifiers uniformly amplify each quadrature of an input field and are of both fundamental and technological importance. We find the quantum limit on the precision of estimating the gain of a quantum-limited…

Quantum Physics · Physics 2022-05-09 Ranjith Nair , Guo Yao Tham , Mile Gu

This paper proposes a multi-mode Gaussian modulated continuous variable quantum key distribution (CV-QKD) scheme able to operate at high bandwidth despite using conventional noisy, coherent detectors. We demonstrate enhancement in shotnoise…

Quantum Physics · Physics 2019-07-24 Rupesh Kumar , Xinke Tang , Adrian Wonfor , Richard Penty , Ian White

Discrete-modulated continuous-variable quantum key distribution protocols are promising candidates for large-scale deployment due to the large technological overlap with deployed modern optical communication devices. The security of…

Quantum Physics · Physics 2020-12-15 Jie Lin , Norbert Lütkenhaus

We describe a continuous variables coherent states quantum key distribution system working at 1550 nm, and entirely made of standard fiber optics and telecom components, such as integrated-optics modulators, couplers and fast InGaAs…

Quantum Physics · Physics 2007-05-23 Jérôme Lodewyck , Thierry Debuisschert , Rosa Tualle-Brouri , Philippe Grangier

The unconditional security of continuous-variable quantum key distribution is established for all schemes based on the estimation of the channel loss and excess noise. It is proved that, in the limit of large keys, Gaussian attacks are…

Quantum Physics · Physics 2010-12-15 Anthony Leverrier , Evgueni Karpov , Philippe Grangier , Nicolas J. Cerf

Current implementations of quantum key distribution (QKD) typically rely on prepare-and-measure (P&M) schemes. Unfortunately, these implementations are not completely secure, unless security proofs fully incorporate all imperfections of…

We show that the maximum transmission distance of continuous-variable quantum key distribution in presence of a Gaussian noisy lossy channel can be arbitrarily increased using a linear noiseless amplifier. We explicitly consider a protocol…

Optical parametric oscillators are among the best-developed quantum light sources, having already been adopted in precision measurement and underpinning various quantum computing and communication paradigms. Meanwhile, progress in photonic…

Quantum Physics · Physics 2025-12-23 Alex O. C. Davis , Alex I. Flint

Continuous-variable quantum key distribution (CV-QKD) enables two remote parties to establish information-theoretically secure keys and offers high practical feasibility due to its compatibility with mature coherent optical communication…

Quantum Physics · Physics 2025-12-18 Yanhao Sun , Jiayu Ma , Xiangyu Wang , Song Yu , Ziyang Chen , Hong Guo

We investigate the security of continuous-variable (CV) quantum key distribution (QKD) using coherent states in the presence of quadrature excess noise. We consider an eavesdropping attack which uses a linear amplifier and beam splitter.…

Quantum Physics · Physics 2009-11-11 Ryo Namiki , Takuya Hirano

We present a discretely modulated continuous-variable quantum key distribution system in free space by using strong coherent states. The amplitude noise in the laser source is suppressed to the shot-noise limit by using a mode cleaner…

Quantum Physics · Physics 2015-05-18 Yong Shen , Hongxin Zou , Liang Tian , Pingxing Chen , Jianmin Yuan

In Measurement-Device-Independent Quantum Key Distribution (MDI-QKD), key rates are significantly reduced due to dispersion in asymmetric channels. This work addresses this issue by utilizing intensity and phase modulators for dispersion…

Quantum Physics · Physics 2024-11-19 Ishan Pandey , Gokul A , Varun Raghunathan

The practical implementation difficulties arising from the Gaussian modulation of the GG02 protocol lead us to investigate the possibilities offered by the combination of probabilistic amplitude shaping technique and quadrature amplitude…