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Related papers: Quantum cryptography using partially entangled sta…

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We consider two quantum cryptographic schemes relying on encoding the key into qudits, i.e. quantum states in a d-dimensional Hilbert space. The first cryptosystem uses two mutually unbiased bases (thereby extending the BB84 scheme), while…

Quantum Physics · Physics 2009-11-07 Nicolas J. Cerf , Mohamed Bourennane , Anders Karlsson , Nicolas Gisin

We demonstrate that a necessary precondition for unconditionally secure quantum key distribution is that sender and receiver can use the available measurement results to prove the presence of entanglement in a quantum state that is…

Quantum Physics · Physics 2009-11-10 Marcos Curty , Maciej Lewenstein , Norbert Lütkenhaus

Quantum key distribution (QKD) is a secure key generation method between two distant parties by wisely exploiting properties of quantum mechanics. In QKD, experimental measurement outcomes on quantum states are transformed by the two…

Quantum Physics · Physics 2010-03-01 Chi-Hang Fred Fung , Xiongfeng Ma , H. F. Chau

Efficiency is a key issue in any real implementation of a cryptographic protocol since the physical resources are not unlimited. We will first show that Quantum Key Distribution is possible with an "Entanglement based" scheme with NPPT…

Quantum Physics · Physics 2015-03-17 Carles Rodó

We propose a quantum key distribution scheme that combines a biased basis choice with the decoy-state method. In this scheme, Alice sends all signal states in the $Z$ basis and decoy states in the $X$ and $Z$ basis with certain…

Quantum Physics · Physics 2013-08-20 Zhengchao Wei , Weilong Wang , Zhen Zhang , Ming Gao , Zhi Ma , Xiongfeng Ma

In general, generation of entangled photon pairs and also the random choice of measurement basis can be implemented with passive optical devices in entanglement based quantum key distribution (QKD) system. However, auxiliary random numbers…

Identifying Bell states without destroying it is frequently dealt with in nowadays quantum technologies such as quantum communication and quantum computing. In practice, quantum entangled states are often distributed among distant parties,…

Quantum Physics · Physics 2024-10-25 Bohdan Bilash , Youngrong Lim , Hyukjoon Kwon , Yosep Kim , Hyang-Tag Lim , Wooyeong Song , Yong-Su Kim

The use of linearly independent signal states in realistic implementations of quantum key distribution (QKD) enables an eavesdropper to perform unambiguous state discrimination. We explore quantitatively the limits for secure QKD imposed by…

Quantum Physics · Physics 2009-10-31 Miloslav Dusek , Mika Jahma , Norbert Lütkenhaus

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

In a conventional quantum (k,n) threshold scheme, a trusted party shares a secret quantum state with n participants such that any k of those participants can cooperate to recover the original secret, while fewer than k participants obtain…

Quantum Physics · Physics 2010-04-13 Qin Li , Dong-Yang Long , W. H. Chan , Dao-Wen Qiu

Quantum cryptography has attracted much attention in recent years. In most existing quantum cryptographic protocols, players usually need the full quantum power of generating, manipulating or measuring quantum states. Semiquantum…

Quantum Physics · Physics 2018-11-12 Ming-Ming Wang , Lin-Ming Gong , Lian-He Shao

Quantum key distribution (QKD) based on coherent states is well known for its implementation simplicity, but it suffers from loss-dependent attacks based on optimal unambiguous state discrimination. Crucially, previous research has…

Quantum Physics · Physics 2020-06-05 Li Liu , Yukun Wang , Emilien Lavie , Arno Ricou , Chao Wang , Fen Zhuo Guo , Charles Ci Wen Lim

Owing to its fundamental principles, quantum theory holds the promise to enhance the security of modern cryptography, from message encryption to anonymous communication, digital signatures, online banking, leader election, one-time…

Quantum Physics · Physics 2025-12-22 Mathieu Bozzio , Claude Crépeau , Petros Wallden , Philip Walther

High-dimensional quantum key distribution (QKD) allows to achieve information-theoretic secure communications, providing high key generation rates which cannot in principle be obtained by QKD protocols with binary encoding. Nonetheless, the…

Quantum Physics · Physics 2020-07-22 I. Vagniluca , B. Da Lio , D. Rusca , D. Cozzolino , Y. Ding , H. Zbinden , A. Zavatta , L. K. Oxenløwe , D. Bacco

We analyse a central broadcast continuous variable quantum key distribution protocol in which a beam produced by a thermal source is used to create a secret key between two parties, Alice and Bob. A beam splitter divides the initial beam…

Quantum Physics · Physics 2021-10-12 Adam Walton , Anne Ghesquière , George Brumpton , David Jennings , Ben Varcoe

Key establishment is a crucial primitive for building secure channels: in a multi-party setting, it allows two parties using only public authenticated communication to establish a secret session key which can be used to encrypt messages.…

Quantum Physics · Physics 2012-06-28 Michele Mosca , Douglas Stebila , Berkant Ustaoglu

In this paper, we propose a novel two-party semiquantum key distribution (SQKD) protocol by only employing one kind of GHZ-like state. The proposed SQKD protocol can create a private key shared between one quantum party with unlimited…

Quantum Physics · Physics 2022-11-03 Tian-Jie Xu , Tian-Yu Ye

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…

Unconditional security in quantum key distribution (QKD) relies on authenticating the identities of users involved in key distribution. While classical identity authentication schemes were initially utilized in QKD implementations, concerns…

Quantum Physics · Physics 2025-02-13 Arindam Dutta , Anirban Pathak

Security of the three-party quantum secret sharing (QSS) schemes based on entanglement and a collective eavesdropping check is analyzed in the case of considerable quantum channel losses. An opaque attack scheme is presented for the…

Quantum Physics · Physics 2007-05-23 Fu-Guo Deng , Xi-Han Li , Hong-Yu Zhou