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Related papers: Amplitude-Phase Modulated CVQKD Protocol

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We propose a novel continuous-variable quantum key distribution (CVQKD) protocol that employs orthogonal frequency-division multiplexing (OFDM) in the terahertz (THz) band to enable high-throughput and secure quantum communication. By…

Quantum Physics · Physics 2025-07-01 Mingqi Zhang , Kaveh Delfanazari

We propose an optimization method for rate-adaptive CV-QKD systems, improving the SKR by up to 15%. A single information reconciliation setup can generate secret keys up to a distance of 112 km. This enables a unified reconciliation system,…

Quantum Physics · Physics 2024-08-19 Erdem Eray Cil , Jonas Berl , Laurent Schmalen

We study achievable rates for four-dimensional (4D) constellations for spectrally efficient optical systems based on a (suboptimal) bit-wise receiver. We show that PM-QPSK outperforms the best 4D constellation designed for uncoded…

Information Theory · Computer Science 2024-01-25 Alex Alvarado , Erik Agrell

We propose a long-distance continuous-variable quantum key distribution (CVQKD) with four-state protocol using non-Gaussian state-discrimination detection. A photon subtraction operation, which is deployed at the transmitter, is used for…

Quantum Physics · Physics 2018-07-23 Qin Liao , Ying Guo , Duang Huang , Peng Huang , Guihua Zeng

Continuous variable quantum key distribution with discrete modulation has the potential to provide information-theoretic security using widely available optical elements and existing telecom infrastructure. While their implementation is…

Quantum Physics · Physics 2024-07-25 Stefan Bäuml , Carlos Pascual-García , Victoria Wright , Omar Fawzi , Antonio Acín

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

Quantum key distribution (QKD) promises provably secure communications. In order to improve the secret key rate, combining a biased basis choice with the decoy-state method is proposed. Concomitantly, there is a basis-independent detection…

Quantum Physics · Physics 2021-08-11 Hua-Lei Yin , Peng Liu , Wei-Wei Dai , Zhao-Hui Ci , Jie Gu , Tian Gao , Qiang-Wei Wang , Zi-Yao Shen

We propose a fully passive twin-field quantum key distribution (QKD) setup where basis choice, decoy-state preparation and encoding are all implemented entirely by post-processing without any active modulation. Our protocol can remove the…

Quantum Physics · Physics 2026-03-25 Wenyuan Wang , Rong Wang , H. F. Chau , Hoi-Kwong Lo

Quantum Key Distribution (QKD) schemes are key exchange protocols based on the physical properties of quantum channels. They avoid the computational-hardness assumptions that underlie the security of classical key exchange.…

Quantum Physics · Physics 2025-12-19 Arpan Akash Ray , Boris Skoric

We propose a novel scheme for continuous variable quantum key distribution(CV-QKD) using the subcarrier multiplexing technique which was employed in microwave photonics. This scheme allows to distribute N channels independent Gaussian…

Quantum Physics · Physics 2014-02-19 Jian Fang , Peng Huang , Guihua Zeng

We designed a CV-QKD system with off-the-shelf components and established the feasibility of distributing 67.6 and 66.8 Mb/s secret key rates on average over a 9.5 km SMF link, using respectively probabilistically shaped 64 and 256 QAM, and…

Recent studies showed the finite-size security of binary-modulation CV-QKD protocols against general attacks. However, they gave poor key-rate scaling against transmission distance. Here, we extend the security proof based on…

Quantum Physics · Physics 2023-08-30 Takaya Matsuura , Shinichiro Yamano , Yui Kuramochi , Toshihiko Sasaki , Masato Koashi

Variations of phase-matching measurement-device-independent quantum key distribution (PM-MDI QKD) protocols have been investigated before, but it was recently discovered that this type of protocol (under the name of twin-field QKD) can beat…

Quantum Physics · Physics 2018-10-30 Jie Lin , Norbert Lütkenhaus

To implement the BB84 decoy-state quantum key distribution (QKD) protocol over a lossy ground-satellite quantum uplink requires a source that has high repetition rate of short laser pulses, long term stability, and no phase correlations…

We use a recent numerical security proof approach to calculate tight secure key rates in the presence of collective attacks for a continuous-variable (CV) eight-state phase-shift keying (8PSK) protocol with heterodyne detection in the…

Quantum Physics · Physics 2022-10-18 Florian Kanitschar , Christoph Pacher

Phase randomization is an important assumption made in many security proofs of practical quantum key distribution (QKD) systems. Here, we present the first experimental demonstration of QKD with reliable active phase randomization. One key…

Quantum Physics · Physics 2009-11-13 Yi Zhao , Bing Qi , Hoi-Kwong Lo

We introduce a polarization agnostic method for Gaussian-modulated coherent state (GCMS) continuous-variable quantum key distribution (CVQKD). Due to the random and continuous nature of the GCMS protocol, Alice, the transmitter, can encode…

Quantum Physics · Physics 2025-04-03 Brian P. Williams , Nicholas A. Peters

We introduce a ternary quantum key distribution (QKD) protocol and asymptotic security proof based on three coherent states and homodyne detection. Previous work had considered the binary case of two coherent states and here we nontrivially…

Quantum Physics · Physics 2018-02-14 Kamil Bradler , Christian Weedbrook

Quantum key distribution(QKD) allows two remote parties to share information-theoretic secret keys. Many QKD protocols assume the phase of encoding state can be continuous randomized from 0 to 2 pi, which, however, may be questionable in…

Quantum Physics · Physics 2023-02-15 Rui Qiang Wang , Zhen Qiang yin , Rong Wang , Shuang Wang , Wei Chen , Guang can Guo , Zhen fu Han

We develop a method to connect the infinite-dimensional description of optical continuous-variable quantum key distribution (QKD) protocols to a finite-dimensional formulation. The secure key rates of the optical QKD protocols can then be…

Quantum Physics · Physics 2021-05-26 Twesh Upadhyaya , Thomas van Himbeeck , Jie Lin , Norbert Lütkenhaus