A GAME THEORETIC APPROACH TO STUDY THE QUANTUM KEY DISTRIBUTION BB84 PROTOCOL

Quantum cryptography uses quantum mechanics to guarantee secure communication. BB84 is a widely used quantum key distribution that provides a way for two parties, a sender, Alice, and a receiver, Bob, to share an unconditionally secure key in the presence of an eavesdropper, Eve. Three different criteria can be assumed to study the BB84 protocol. They are the efficiency of the protocol, the probability that Eve remains undetected, and the amount of knowledge Eve has about Alice's bit sequence. In a previous approach, we only considered the probability that Eve remains undetected. We viewed this protocol as a three player static game in which Alice and Bob were two cooperative players and Eve was a competitive one. In our game model, Alice's and Bob's objective was to maximize the probability of detecting Eve, while Eve's objective was to minimize this probability. In this paper, our previous effort is extended and we also consider the other two criteria, i.e. the efficiency of the protocol and the amount of knowledge Eve has about Alice's bit sequence. Using these models, we show how game theory can be used to find the strategies for Alice, Bob and Eve.

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DECOY STATE QUANTUM KEY DISTRIBUTION

International Journal of Quantum Information ◽

10.1142/s0219749905001328 ◽

2005 ◽

Vol 03 (supp01) ◽

pp. 143-143 ◽

Cited By ~ 4

Author(s):

HOI-KWONG LO

Keyword(s):

Quantum Key Distribution ◽

Secure Communication ◽

Key Distribution ◽

Generation Rate ◽

Key Generation ◽

Long Distance ◽

Decoy State ◽

Bb84 Protocol ◽

High Loss ◽

Statistical Fluctuations

Quantum key distribution (QKD) allows two parties to communicate in absolute security based on the fundamental laws of physics. Up till now, it is widely believed that unconditionally secure QKD based on standard Bennett-Brassard (BB84) protocol is limited in both key generation rate and distance because of imperfect devices. Here, we solve these two problems directly by presenting new protocols that are feasible with only current technology. Surprisingly, our new protocols can make fiber-based QKD unconditionally secure at distances over 100km (for some experiments, such as GYS) and increase the key generation rate from O(η2) in prior art to O(η) where η is the overall transmittance. Our method is to develop the decoy state idea (first proposed by W.-Y. Hwang in "Quantum Key Distribution with High Loss: Toward Global Secure Communication", Phys. Rev. Lett. 91, 057901 (2003)) and consider simple extensions of the BB84 protocol. This part of work is published in "Decoy State Quantum Key Distribution", . We present a general theory of the decoy state protocol and propose a decoy method based on only one signal state and two decoy states. We perform optimization on the choice of intensities of the signal state and the two decoy states. Our result shows that a decoy state protocol with only two types of decoy states—a vacuum and a weak decoy state—asymptotically approaches the theoretical limit of the most general type of decoy state protocols (with an infinite number of decoy states). We also present a one-decoy-state protocol as a special case of Vacuum+Weak decoy method. Moreover, we provide estimations on the effects of statistical fluctuations and suggest that, even for long distance (larger than 100km) QKD, our two-decoy-state protocol can be implemented with only a few hours of experimental data. In conclusion, decoy state quantum key distribution is highly practical. This part of work is published in "Practical Decoy State for Quantum Key Distribution", . We also have done the first experimental demonstration of decoy state quantum key distribution, over 15km of Telecom fibers. This part of work is published in "Experimental Decoy State Quantum Key Distribution Over 15km", .

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Equilibrium and incentives for supervisor–postgraduate collaborations: A game-theoretic approach

RAIRO - Operations Research ◽

10.1051/ro/2018067 ◽

2019 ◽

Vol 53 (5) ◽

pp. 1729-1747 ◽

Cited By ~ 2

Author(s):

Qinglong Gou ◽

Xinyu Wang ◽

Juzhi Zhang

Keyword(s):

Educational System ◽

Collaborative Work ◽

Game Model ◽

Theoretic Approach ◽

Joint Work ◽

Postgraduate Students ◽

Incentive Strategies ◽

Game Theoretic ◽

The Relationship ◽

Game Theoretic Approach

In most universities, supervisors collaborate with their postgraduate students in writing papers. As a consequence, the relationship between supervisors and postgraduates in the collaborative work becomes the most important one among various relationships between them. In this paper, using a game model, we show that in the current educational system of China, there is a dilemma between supervisors and their postgraduates for their collaborative work – in most cases, either the supervisor or the students will not spend any effort in their joint work. After that, we also investigate whether the two common incentive strategies, i.e., (i) incentives to students, and (ii) incentives to faculties, can solve this dilemma. Our results show that a university can solve the problem by either (i) just using strong incentives to postgraduate students, or (ii) by using a combination of a normal incentive to students and a strong incentive to faculties. Also, we find that when the incentives to the students and to the faculties are below a certain level, all incentives will be just in vain – neither can they improve the serious relationship between supervisors and their postgraduates, nor can they improve the paper quality.

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Study on Quantum Key Distribution

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.275-277.2515 ◽

2013 ◽

Vol 275-277 ◽

pp. 2515-2518

Author(s):

Xiao Qiang Guo ◽

Cui Ling Luo ◽

Yan Yan

Keyword(s):

Quantum Mechanics ◽

Quantum Key Distribution ◽

Secure Communication ◽

Key Distribution ◽

Secret Key ◽

Bb84 Protocol

Quantum key distribution (QKD) uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages. QKD is a research hotspot of international academia in recent years. We introduce some protocols: BB84 protocol, E91 protocol, SARG04 protocol.

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