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Related papers: Secrecy content of two-qubit states

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In practical quantum key distribution (QKD) system, the state preparation and measurement are imperfect comparing with the ideal BB84 protocol, which are always state-dependent in practical realizations. If the state-dependent imperfections…

Quantum Physics · Physics 2011-12-21 Hong-Wei Li , Zhen-Qiang Yin , Zheng-Fu Han , Wan-Su Bao , Guang-Can Guo

This paper is withdrawn. We study the quantum key distribution (QKD) protocol based on a quantum retrodiction protocol, namely the so-called mean king problem. The security is analyzed by considering the eavesdropping on both the…

Quantum Physics · Physics 2013-01-15 Han-Duo Shi , Yi-Nan Wang , Li Jing , Ru-Quan Wang , Liang-Zhu Mu , Heng Fan

Two quantum key agreement protocols using Bell states and Bell measurement were recently proposed by Shukla et al.(Quantum Inf. Process. 13(11), 2391-2405, 2014). However, Zhu et al. pointed out that there are some security flaws and…

Quantum Physics · Physics 2024-05-14 Wen-Jie Liu , Yong Xu , Ching-Nung Yang , Pei-Pei Gao , Wen-Bin Yu

We propose efficient-phase-encoding protocols for continuous-variable quantum key distribution using coherent states and postselection. By these phase encodings, the probability of basis mismatch is reduced and total efficiency is…

Quantum Physics · Physics 2008-09-29 Ryo Namiki , Takuya Hirano

In conventional quantum key distribution protocols, the secure key is normally extracted from the measurement outcomes of the system. Here, a different approach is proposed, where the secure key is extracted from the measurement bases,…

Quantum Physics · Physics 2014-10-21 Xiongfeng Ma

We consider the discrimination of two-party quantum states and provide a quantum data-hiding scheme using two-qubit separable states. We first provide a bound on the optimal local discrimination of two-party quantum states, and establish a…

Quantum Physics · Physics 2025-12-18 Donghoon Ha , Jeong San Kim

We present a protocol for quantum cryptographic network consisting of a quantum network center and many users, in which any pair of parties with members chosen from the whole users on request can secure a quantum key distribution by help of…

Quantum Physics · Physics 2007-05-23 Sora Choi , Soojoon Lee , Dong Pyo Chi

It is proven that recently introduced states with perfectly secure bits of cryptographic key (private states representing secure bit) [K. Horodecki et al., Phys. Rev. Lett. 94, 160502 (2005)] as well as its multipartite and higher dimension…

Quantum Physics · Physics 2007-11-07 Pawel Horodecki , Remigiusz Augusiak

It is known that measurement-device-independent quantum key distribution (MDI-QKD) provides ultimate security from all types of side-channel attack against detectors at the expense of low key generation rate. Here, we propose MDI-QKD using…

Quantum Physics · Physics 2017-03-08 Yonggi Jo , Wonmin Son

We consider distillation of entanglement from two qubit states which are mixtures of three mutually orthogonal states: two pure entangled states and one pure product state. We distill entanglement from such states by projecting n copies of…

Most qubit-based quantum key distribution (QKD) protocols extract the secure key merely from single-photon component of the attenuated lasers. However, with the Scarani-Acin-Ribordy-Gisin 2004 (SARG04) QKD protocol, the unconditionally…

Quantum Physics · Physics 2016-07-11 Hua-Lei Yin , Yao Fu , Yingqiu Mao , Zeng-Bing Chen

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…

The notions of privacy tests and $k$-extendible states have both been instrumental in quantum information theory, particularly in understanding the limits of secure communication. In this paper, we determine the maximum probability with…

Quantum Physics · Physics 2025-11-07 Vishal Singh , Karol Horodecki , Aby Philip , Mark M. Wilde

We show how to calculate the secure final key rate in the four-intensity decoy-state MDI-QKD protocol with both source errors and statistical fluctuations with a certain failure probability. Our results rely only on the range of only a few…

Quantum Physics · Physics 2017-11-01 Cong Jiang , Zong-Wen Yu , Xiang-Bin Wang

One of the most prominent techniques to enhance the performance of practical quantum key distribution (QKD) systems with laser sources is the decoy-state method. Current decoy-state QKD setups operate at GHz repetition rates, a regime where…

Quantum Physics · Physics 2023-04-13 Xoel Sixto , Víctor Zapatero , Marcos Curty

We present a protocol for quantum key distribution using discrete modulation of coherent states of light. Information is encoded in the variable phase of coherent states which can be chosen from a regular discrete set ranging from binary to…

Quantum Physics · Physics 2015-05-13 Denis Sych , Gerd Leuchs

A quantum key distribution scheme based on the use of displaced squeezed vacuum states is presented. The states are squeezed in one of two field quadrature components, and the value of the squeezed component is used to encode a character…

Quantum Physics · Physics 2009-10-31 Mark Hillery

Any Quantum Key Distribution (QKD) protocol consists first of sequences of measurements that produce some correlation between classical data. We show that these correlation data must violate some Bell inequality in order to contain…

Quantum Physics · Physics 2009-11-11 Antonio Acin , Nicolas Gisin , Lluis Masanes

Entanglement distillation, the process of converting weakly entangled states into maximally entangled ones using Local Operations and Classical Communication (LOCC), is pivotal for robust entanglement-assisted quantum information processing…

Quantum Physics · Physics 2025-12-17 Christopher Popp , Tobias C. Sutter , Beatrix C. Hiesmayr

We propose the improved decoy state quantum key distribution incorporating finite statistics due to the finite code length and report on its demonstration. In our experiment, four different intensities including the vacuum state for optimal…

Quantum Physics · Physics 2007-05-23 Jun Hasegawa , Masahito Hayashi , Tohya Hiroshima , Akihiro Tanaka , Akihisa Tomita