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Related papers: Longer distance continuous variable quantum key di…

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In this paper we investigate the security of continuous variable BB84 quantum key distribution protocol using single photon added then subtracted squeezed coherent state SPASSCS. It's found that the SPASSCS is a non-Gaussian and…

Quantum Physics · Physics 2022-08-30 Youssef Oulouda , Mohamed El Falaki , Mohamed Daoud

We extend the security proof for continuous variable quantum key distribution protocols using post selection to account for arbitrary eavesdropping attacks by employing the concept of an equivalent protocol where the post-selection is…

Quantum Physics · Physics 2013-03-08 Nathan Walk , Thomas Symul , Ping Koy Lam , Timothy C. Ralph

We examine security of a protocol on cryptographic key distribution via classical noise proposed by Yuen and Kim (Phys. Lett. A 241 135 (1998)). Theoretical and experimental analysis in terms of the secure key distribution rate shows that…

Quantum Physics · Physics 2009-11-06 Akihisa Tomita , Osamu Hirota

The calibration of a quantum channel, i.e. the determination of the transmission losses affecting it, is definitely one of the principal objectives in both the quantum communication and quantum metrology frameworks. Another task of the…

In theory, quantum key distribution (QKD) allows secure communications between two parties based on physical laws. However, most of the security proofs of QKD today make unrealistic assumptions and neglect many relevant device…

Quantum Physics · Physics 2019-08-06 Margarida Pereira , Marcos Curty , Kiyoshi Tamaki

Entanglement based quantum communication offers an increased level of security in practical secret shared key distribution. One of the fundamental principles enabling this security -- the fact that interfering with one photon will destroy…

Quantum key distribution is an effective encryption technique which can be used to perform secure quantum communication between satellite and ground stations. Quantum cryptography enhances security in various networks such as optical fibers…

Quantum Physics · Physics 2018-07-20 Vishal Sharma , Subhashish Banerjee

Quantum key distribution allows for the generation of a secret key between distant parties connected by a quantum channel such as optical fibre or free space. Unfortunately, the rate of generation of a secret key by direct transmission is…

Quantum key distribution with decoherence-free subspaces has been proposed to overcome the collective noise to the polarization modes of photons flying in quantum channel. Prototype of this scheme have also been achieved with…

Quantum Physics · Physics 2008-06-19 Zhen-Qiang Yin , Yi-Bo Zhao , Zheng-Wei Zhou , Zheng-Fu Han , Guang-Can Guo

Implementation of a twin-field quantum key distribution network faces limitations, including the low tolerance of interference errors for phase-matching type protocols and the strict constraint regarding intensity and probability for…

Quantum Physics · Physics 2023-04-11 Yuan-Mei Xie , Chen-Xun Weng , Yu-Shuo Lu , Yao Fu , Yang Wang , Hua-Lei Yin , Zeng-Bing Chen

Use of low-noise detectors can both increase the secret bit rate of long-distance quantum key distribution (QKD) and dramatically extend the length of a fibre optic link over which secure key can be distributed. Previous work has…

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

Standard quantum key distribution (QKD) protocols typically assume that the distant parties share a common reference frame. In practice, however, establishing and maintaining a good alignment between distant observers is rarely a trivial…

Quantum Physics · Physics 2014-04-04 Joshua A. Slater , Cyril Branciard , Nicolas Brunner , Wolfgang Tittel

We discuss a quantum key distribution scheme in which small phase and amplitude modulations of quantum limited, CW light beams carry the key information. We identify universal constraints on the level of shared information between the…

Quantum Physics · Physics 2007-05-23 T. C. Ralph

Chromatic dispersion is one of the main limitations to the security of quantum communication protocols that rely on the transmission of single photons in single mode fibers. This phenomenon forces the trusted parties to define longer…

Quantum Physics · Physics 2017-02-14 Karolina Sedziak , Mikołaj Lasota , Piotr Kolenderski

Continuous variable quantum key distribution bears the promise of simple quantum key distribution directly compatible with commercial off the shelf equipment. However, for a long time its performance was hindered by the absence of good…

Quantum Physics · Physics 2025-06-18 Jesus Martinez-Mateo , David Elkouss

Continuous Variable (CV) quantum key distribution (QKD) is a promising candidate for practical implementations due to its compatibility with the existing communication technology. A trusted device scenario assuming that an adversary has no…

Quantum Physics · Physics 2023-05-30 Shinichiro Yamano , Takaya Matsuura , Yui Kuramochi , Toshihiko Sasaki , Masato Koashi

Quantum optical states are fragile and can become corrupted when passed through a lossy communication channel. Unlike for classical signals, optical amplifiers cannot be used to recover quantum signals. Quantum repeaters have been proposed…

Quantum Physics · Physics 2017-02-15 Josephine Dias , Timothy C Ralph

We present two new schemes for quantum key distribution (QKD) that neither require entanglement nor an ideal single-photon source, making them implementable with commercially available single-photon sources. These protocols are shown to be…

Quantum Physics · Physics 2025-05-13 Arindam Dutta , Anirban Pathak

The length of a secure link over which a quantum key can be distributed depends on the efficiency and dark-count rate of the detectors used at the receiver. We report on the first demonstration of quantum key distribution using…