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The secure transfer of information is an important problem in modern telecommunications. Quantum key distribution (QKD) provides a solution to this problem by using individual quantum systems to generate correlated bits between remote…

Quantum Physics · Physics 2013-08-02 S. Etcheverry , G. Cañas , E. S. Gómez , W. A. T. Nogueira , C. Saavedra , G. B. Xavier , G. Lima

Quantum entanglement plays a pivotal role in many communication protocols, like secret sharing and quantum cryptography. We consider a scenario where more than two parties are involved in a protocol and share a multipartite entangled state.…

Quantum Physics · Physics 2020-05-06 Arpan Das , Sumit Nandi , Sk Sazim , Pankaj Agrawal

The advent of quantum key distribution (QKD) has revolutionized secure communication by providing unconditional security, unlike classical cryptographic methods. However, its effectiveness relies on robust identity authentication, as…

Quantum Physics · Physics 2025-08-11 Arindam Dutta

We propose a new Quantum Key Distribution method in which Alice sends pairs of qubits to Bob, each in one of four possible states. Bob uses one qubit to generate a secure key and the other to generate an auxiliary key. For each pair he…

Quantum Physics · Physics 2015-05-01 Mohd Asad Siddiqui , Tabish Qureshi

Quantum Key Distribution (QKD) allows unconditionally secure communication based on the laws of quantum mechanics rather then assumptions about computational hardness. Optimizing the operation parameters of a given QKD implementation is…

In this work, we present a novel authenticated Quantum Key Distribution (QKD) protocol employing maximally entangled qubit pairs. In the absence of noise, we securely authenticate the well-known BB84 QKD scheme under two assumptions: first,…

Quantum Physics · Physics 2025-10-22 Pol Julià Farré , Vladlen Galetsky , Soham Ghosh , Janis Nötzel , Christian Deppe

We introduce a new relativistic orthogonal states quantum key distribution protocol which leverages the properties of both quantum mechanics and special relativity to securely encode multiple bits onto the spatio-temporal modes of a single…

Quantum Physics · Physics 2014-06-12 Jordan S. Cotler , Peter W. Shor

Quantum Key Distribution (QKD) with classical Bob has recently been suggested and proven robust. Following this work, QKD with classical Alice was also suggested and proven robust. The above protocols are ideal in the sense that they make…

Quantum Physics · Physics 2010-12-15 Michel Boyer , Tal Mor

A real-time Quantum Key Distribution System is developed in this paper. In the system, based on the feature of Field Programmable Gate Array (FPGA), secure key extraction control and algorithm have been optimally designed to perform…

Quantum key distribution (QKD) offers a secret way to share keys between legitimate users which is guaranteed by the law of quantum mechanics. Most recently, the limitation of transmission distance without quantum repeaters was broken…

Quantum Physics · Physics 2019-06-19 Xingyu Zhou , Chunhui Zhang , Chunmei Zhang , Qin Wang

We demonstrate a prototype-implementation of deterministic information encoding for quantum key distribution (QKD) following the ping-pong coding protocol [K. Bostroem, T. Felbinger, Phys. Rev. Lett. 89 (2002) 187902-1]. Due to the…

Quantum Physics · Physics 2009-11-13 Martin Ostermeyer , Nino Walenta

Cryptanalysis is an important branch in the study of cryptography, including both the classical cryptography and the quantum one. In this paper we analyze the security of two three-party quantum key distribution protocols (QKDPs) proposed…

Quantum Physics · Physics 2011-04-21 Fei Gao , Su-Juan Qin , Fen-Zhuo Guo , Qiao-Yan Wen

As an important imaging technique, holography has been realized with different physical dimensions of light,including polarization, wavelength, and time. Recently, quantum holography has been realized by utilizing polarization entangled…

Optics · Physics 2023-02-06 Ling-Jun Kong , Yifan Sun , Furong Zhang , Jingfeng Zhang , Xiangdong Zhang

We propose a bipartite quantum key distribution (QKD) protocol based on causal nonseparability: the presence of a resource -- a process matrix -- that does not correspond to any definite causal order between two parties. In our protocol,…

Since the invention of Bennett-Brassard 1984 (BB84) protocol, many quantum key distribution (QKD) protocols have been proposed and some protocols are operated even in field environments. One of the striking features of QKD is that QKD…

Quantum Physics · Physics 2016-01-18 Hiroki Takesue , Toshihiko Sasaki , Kiyoshi Tamaki , Masato Koashi

We report on a complete experimental implementation of a quantum key distribution protocol through a free space link using polarization-entangled photon pairs from a compact parametric down-conversion source. Over 10 hours of uninterrupted…

Quantum Physics · Physics 2007-05-23 Ivan Marcikic , Antia Lamas-Linares , Christian Kurtsiefer

In this paper we consider the quantum repeater protocol for distributing the entanglement to two distant three-level atoms. In this protocol, we insert six atoms between two target atoms such that the eight considered atoms are labeled by…

Quantum Physics · Physics 2021-06-04 M Ghasemi , M K Tavassoly

In this paper, we present a fully fiber-based one-way Quantum Key Distribution (QKD) system implementing the Gaussian-Modulated Coherent States (GMCS) protocol. The system employs a double Mach-Zehnder Interferometer (MZI) configuration in…

Quantum Physics · Physics 2009-11-13 Bing Qi , Lei-Lei Huang , Li Qian , Hoi-Kwong Lo

Random generation and confidential distribution of cryptographic keys are fundamental building blocks of secure communication. Using quantum states in which the transmitted quantum bit is entangled with a stationary memory quantum bit…

Quantum Physics · Physics 2021-11-30 Pascal Kobel , Ralf A. Berner , Michael Köhl

Fiber-based quantum communication networks are currently limited without quantum repeaters. Satellite-based quantum links have been proposed to extend the network domain. We have developed a quantum communication system, suitable for…

Quantum Physics · Physics 2022-10-27 Joseph C. Chapman , Charles C. W. Lim , Paul G. Kwiat