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Related papers: Picture-perfect Quantum Key Distribution

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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

Secure communication protocols are becoming increasingly important, e.g. for internet-based communication. Quantum key distribution allows two parties, commonly called Alice and Bob, to generate a secret sequence of 0s and 1s called a key…

Physics Education · Physics 2017-04-05 Antje Kohnle , Aluna Rizzoli

Quantum key distribution (QKD) offers information-theoretic security based on the fundamental laws of physics. However, device imperfections, such as those in active modulators, may introduce side-channel leakage, thus compromising…

Quantum Physics · Physics 2023-05-10 Chengqiu Hu , Wenyuan Wang , Kai-Sum Chan , Zhenghan Yuan , Hoi-Kwong Lo

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

Quantum key distribution is a key application of quantum mechanics, shaping the future of privacy and secure communications. Many protocols require single photons, often approximated by strongly attenuated laser pulses. Here, we harness the…

Since the introduction of quantum computation by Richard Feynman in 1982, Quantum computation has shown exemplary results in various applications of computer science including unstructured database search, factorization, molecular…

Quantum Physics · Physics 2020-07-29 Hemant Rana , Nitin Verma

We prove the security of the Bennett-Brassard (BB84) quantum key distribution protocol in the case where the source and detector are under the limited control of an adversary. Our proof applies when both the source and the detector have…

Quantum Physics · Physics 2007-05-23 Daniel Gottesman , Hoi-Kwong Lo , Norbert Lütkenhaus , John Preskill

Using the axiomatic definition of the coherence measure, such as the $l_{1}$ norm and the relative entropy, we study the phenomena of two-qubit system quantum coherence through quantum channels where successive uses of the channels are…

Quantum Physics · Physics 2016-12-30 You-neng Guo , Ke Zeng , Qing-long Tian , Zheng-da Li

Quantum key distribution (QKD) is a provably secure way of generating a secret key, which can later be used for encoding and decoding information. In this paper we analyze the effects of an eavesdropper's variable-strength measurements on…

Quantum Physics · Physics 2025-10-01 Yuval Idan , Tal Gofman , Ziv Abelson , Isabelle Cestier , Elad Mentovich , Eliahu Cohen

We suggest that the randomness of the choices of measurement basis by Alice and Bob provides an additional important resource for quantum cryptography. As a specific application, we present a novel protocol for quantum key distribution…

Quantum Physics · Physics 2016-08-16 Hannes R. Böhm , Paul S. Böhm , Markus Aspelmeyer , Časlav Brukner , Anton Zeilinger

Quantum key distribution (QKD) offers the promise of absolutely secure communications. However, proofs of absolute security often assume perfect implementation from theory to experiment. Thus, existing systems may be prone to insidious…

Quantum Physics · Physics 2014-06-23 Samuel L. Braunstein , Stefano Pirandola

We consider a continuous-variable (CV) quantum key distribution (QKD) protocol over free-space channels, which is simpler and more robust than typical CV QKD protocols. It uses a bright laser, squeezed and modulated in the amplitude…

Quantum Physics · Physics 2022-03-14 Nedasadat Hosseinidehaj , Matthew S. Winnel , Timothy C. Ralph

Digital signal processing technology has paved the way for the realization of high-speed continuous-variable quantum key distribution systems. However, existing security proofs are limited to static digital signal processing algorithms,…

Quantum Physics · Physics 2026-02-06 Lu Fan , Zhengyu Li , Sheng Liu , Xuesong Xu , Tianyu Zhang , Jiale Mi , Dong Wang , Dechao Zhang , Han Li , Song Yu , Yichen Zhang

Quantum key distribution (QKD) protocols most often use two conjugate bases in order to verify the security of the quantum channel. In the majority of protocols, these bases are mutually unbiased to one another, which is to say they are…

Now that fundamental quantum principles of indeterminacy and measurement have become the basis of new technologies that provide secrecy between two communicating parties, there is a need to provide teaching laboratories that illustrate how…

Quantum Physics · Physics 2021-02-03 Aayam Bista , Baibhav Sharma , Enrique J. Galvez

Quantum continuous variables are being explored as an alternative means to implement quantum key distribution, which is usually based on single photon counting. The former approach is potentially advantageous because it should enable higher…

Quantum Physics · Physics 2009-11-10 F. Grosshans , G. Van Assche , J. Wenger , R. Brouri , N. J. Cerf , Ph. Grangier

We study information theoretical security for space links between a satellite and a ground-station. Quantum key distribution (QKD) is a well established method for information theoretical secure communication, giving the eavesdropper…

Quantum Physics · Physics 2021-07-07 A. Vazquez-Castro , D. Rusca , H. Zbinden

Existing quantum cryptographic schemes are not, as they stand, operable in the presence of noise on the quantum communication channel. Although they become operable if they are supplemented by classical privacy-amplification techniques, the…

Quantum Physics · Physics 2009-01-23 D. Deutsch , A. Ekert , R. Jozsa , C. Macchiavello , S. Popescu , A. Sanpera

Quantum Key Distribution (QKD) protocols enable two distant parties to communicate with information-theoretically proven secrecy. However, these protocols are generally vulnerable to potential mismatches between the physical modeling and…

Quantum Physics · Physics 2026-01-22 Corentin Lanore , Xavier Valcarce , Jean Etesse , Anthony Martin , Jean-Daniel Bancal

Key distribution plays a fundamental role in cryptography. Currently, the quantum scheme stands as the only known method for achieving unconditionally secure key distribution. This method has been demonstrated over distances of 508 and 1002…

Quantum Physics · Physics 2024-08-27 Hua-Lei Yin