scholarly journals Multi-partite quantum cryptographic protocols with noisy GHZ states

2007 ◽  
Vol 7 (8) ◽  
pp. 689-715
Author(s):  
K. Chen ◽  
H.-K. Lo
Keyword(s):  
Bipartite Graph ◽  
Wide Class ◽  
Key Agreement ◽  
Bell Inequalities ◽  
Cryptographic Protocols ◽  
Entangled States ◽  
Threshold Values ◽  
Initial State ◽  
Graph States ◽  
Ghz States

We propose a wide class of distillation schemes for multi-partite entangled states that are CSS-states. Our proposal provides not only superior efficiency, but also new insights on the connection between CSS-states and bipartite graph states. We then apply our distillation schemes to the tri-partite case for three cryptographic tasks---namely, (a) conference key agreement, (b) quantum sharing of classical secrets and (c) third-man cryptography. Moreover, we construct ``prepare-and-measure'' protocols for the above three cryptographic tasks which can be implemented with the generation of only a single entangled pair at a time. This gives significant simplification over previous experimental implementations which require two entangled pairs generated simultaneously. We also study the yields of those protocols and the threshold values of the fidelity above which the protocols can function securely. Rather surprisingly, our protocols will function securely even when the initial state does not violate the standard Bell-inequalities for GHZ states.

Controlled quantum key agreement based on maximally three-qubit entangled states

2020 ◽  
Vol 34 (18) ◽  
pp. 2050201
Author(s):  
Jie Tang ◽  
Lei Shi ◽  
Jiahua Wei
Keyword(s):  
Performance Analysis ◽  
Key Agreement ◽  
Entangled States ◽  
Quantum Key Agreement ◽  
Ghz States ◽  
Participant Attack ◽  
Significant Change

In this paper, we propose a two-party and a three-party controlled quantum key agreement (QKA) protocols with three-qubit GHZ states and Bell measurements. Compared with previous protocols, the significant change of our schemes is that a supervisor is introduced for controlling the agreement process to improve the controllability. Moreover, our protocols ensure each communication participant contribute equally to the agreement keys, and all participants can negotiate the shared keys without exchanging classical bits between them. The performance analysis shows that our protocols can be immune to outsider and participant attack.

scholarly journals Can We Entangle Entanglement?

2021 ◽  
Author(s):  
Mrittunjoy Guha Majumdar
Keyword(s):  
Quantum Teleportation ◽  
Entangled States ◽  
Controlled Teleportation ◽  
Xy Model ◽  
Graph States ◽  
Ghz States ◽  
Remote Locations ◽  
Potential Applications ◽  
Fractal Network ◽  
Qubit States

In this chapter, nested multilevel entanglement is formulated and discussed in terms of Matryoshka states. The generation of such states that contain nested patterns of entanglement, based on an anisotropic XY model has been proposed. Two classes of multilevel-entanglement- the Matryoshka Q-GHZ states and Matryoshka generalised GHZ states, are studied. Potential applications of such resource states, such as for quantum teleportation of arbitrary one, two and three qubits states, bidirectional teleportation of arbitrary two qubit states and probabilistic circular controlled teleportation are proposed and discussed, in terms of a Matryoshka state over seven qubits. We also discuss fractal network protocols, surface codes and graph states as well as generation of arbitrary entangled states at remote locations in this chapter.

N-measurement Bell inequalities, N-atom entangled states, and the nonlocality of one photon

1991 ◽  
Vol 160 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Lucien Hardy
Keyword(s):  
Bell Inequalities ◽  
Entangled States

Teleportation and dense coding via a multiparticle quantum channel of the GHZ-class

2002 ◽  
Vol 2 (5) ◽  
pp. 367-378
Author(s):  
V.N. Gorbachev ◽  
A.I. Zhiliba ◽  
A.I. Trubilko ◽  
A.A. Rodichkina
Keyword(s):  
Quantum Channel ◽  
Entangled States ◽  
Dense Coding ◽  
Ghz States ◽  
Classical Capacity ◽  
Coding Schemes ◽  
One To One

A set of protocols for teleportation and dense coding schemes based on a multiparticle quantum channel, represented by the $N$-particle entangled states of the GHZ class, is introduced. Using a found representation for the GHZ states, it was shown that for dense coding schemes enhancement of the classical capacity of the channel due from entanglement is $N/N-1$. Within the context of our schemes it becomes clear that there is no one-to one correspondence between teleportation and dense coding schemes in comparison when the EPR channel is exploited. A set of schemes, for which two additional operations as entanglement and disentanglement are permitted, is considered.

scholarly journals Bell Inequalities for Graph States

2005 ◽  
Vol 95 (12) ◽  
Author(s):  
Otfried Gühne ◽  
Géza Tóth ◽  
Philipp Hyllus ◽  
Hans J. Briegel
Keyword(s):  
Bell Inequalities ◽  
Graph States

Generation of four-photon polarization entangled states with cross-Kerr nonlinearity

2015 ◽  
Vol 13 (05) ◽  
pp. 1550024 ◽  
Author(s):  
Meiyu Wang ◽  
Fengli Yan
Keyword(s):  
Kerr Nonlinearity ◽  
Entangled States ◽  
Entangled State ◽  
Kerr Medium ◽  
Coherent Light ◽  
Photon Polarization ◽  
Beam Splitters ◽  
Ghz States ◽  
Different Types ◽  
Quantum Optical

We show how to prepare three different types of four-photon polarization entangled states among four modes. The scheme only use cross-Kerr medium, polarization beam splitters and X homodyne measurements on coherent light fields, which can be efficiently implemented in quantum optical laboratories. GHZ states and symmetric Dick states can be generated in deterministic way based on the scheme. With the possible availability of suitable strong Kerr nonlinearity, another type of entangled state called genuine four-photon entangled state can be realized as well.

Two-party quantum key agreement protocol with four-particle entangled states

2016 ◽  
Vol 30 (26) ◽  
pp. 1650332 ◽  
Author(s):  
Yefeng He ◽  
Wenping Ma
Keyword(s):  
Key Agreement ◽  
Security Analysis ◽  
Information Leakage ◽  
Quantum States ◽  
Entangled States ◽  
Correlation Property ◽  
Quantum Key Agreement ◽  
Key Agreement Protocol ◽  
Delayed Measurement ◽  
Quantum Key Agreement Protocol

Based on four-particle entangled states and the delayed measurement technique, a two-party quantum key agreement protocol is proposed in this paper. In the protocol, two participants can deduce the measurement results of each other’s initial quantum states in terms of the measurement correlation property of four-particle entangled states. According to the corresponding initial quantum states deduced by themselves, two parties can extract the secret keys of each other by using the publicly announced value or by performing the delayed measurement, respectively. This guarantees the fair establishment of a shared key. Since each particle in quantum channel is transmitted only once, the protocol is congenitally free from the Trojan horse attacks. The security analysis shows that the protocol not only can resist against both participant and outsider attacks but also has no information leakage problem. Moreover, it has high qubit efficiency.

scholarly journals Generalized Ardehali-Bell inequalities for graph states

2008 ◽  
Vol 77 (3) ◽  
Author(s):  
Otfried Gühne ◽  
Adán Cabello
Keyword(s):  
Bell Inequalities ◽  
Graph States

scholarly journals A New Enhanced Authentication Mechanism Using Session Key Agreement Protocol

2018 ◽  
Vol 18 (4) ◽  
pp. 61-74 ◽  
Author(s):  
S. Usha ◽  
S. Kuppuswami ◽  
M. Karthik
Keyword(s):  
Information Security ◽  
Key Agreement ◽  
Cryptographic Protocols ◽  
Personal Privacy ◽  
Session Key ◽  
Driving License ◽  
Key Agreement Protocol ◽  
Authentication Mechanism ◽  
Session Key Agreement ◽  
Security Properties

Abstract Cryptographic protocols are the backbone of information security. Unfortunately the security of several important components of these protocols can be neglected. This causes violation of personal privacy and threats to democracy. Integration of biometrics with cryptography can overcome this problem. In this paper an enhanced session key agreement protocol which uses the data derived from iris signature is suggested to improve the security of biometric based applications like e-Passport, e-Driving license, etc. The authenticity and security properties of the proposed protocol are analyzed using ProVerif tool and demonstrate it satisfies the intended properties.

An Improved Ping-Pong Protocol Using Three-Qubit Nonmaximally Nonorthogonal Entangled States

2019 ◽  
Vol 74 (9) ◽  
pp. 799-811
Author(s):  
Hargeet Kaur ◽  
Atul Kumar
Keyword(s):  
Information Transfer ◽  
Orthogonal Basis ◽  
Basis Set ◽  
Entangled States ◽  
Ghz States ◽  
Ping Pong ◽  
Orthogonal Set ◽  
Qubit States ◽  
Single Receiver ◽  
Qubit Efficiency

AbstractWe analyse the ping-pong (PP) protocol [K. Bostrom and T. Felbinger, Phys. Rev. Lett. 89, 187902 (2002)] using different sets of partially entangled three-qubit states. Interestingly, our results show that the partially entangled nonorthogonal three-qubit states are more useful as resources in comparison to three-qubit maximally entangled Greenberger–Horne–Zeilinger (GHZ) states. The properties of orthogonal set of partially entangled states as resources for PP protocol, however, are similar to that of maximally entangled GHZ states – both the states are not preferable due to the vulnerability towards eavesdropping. On the other hand, partially entangled nonorthogonal basis set holds importance for transferring two-bit information, one each from a sender, to a single receiver. The protocol is further analysed for various eavesdropping attacks, and the results are compared with the use of two shared Bell pairs for two-bit information transfer. Surprisingly, the use of partially entangled nonorthogonal set of states is found to offer better qubit efficiency and increased security, as against the use of two separate maximally entangled Bell states with orthogonal basis. In addition, we also propose a mixed-state sharing protocol to further enhance the security of the PP protocol.

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