3,626 research outputs found
Repeatable classical one-time-pad crypto-system with quantum mechanics
Classical one-time-pad key can only be used once. We show in this Letter that
with quantum mechanical information media classical one-time-pad key can be
repeatedly used. We propose a specific realization using single photons. The
reason why quantum mechanics can make the classical one-time-pad key repeatable
is that quantum states can not be cloned and eavesdropping can be detected by
the legitimate users. This represents a significant difference between
classical cryptography and quantum cryptography and provides a new tool in
designing quantum communication protocols and flexibility in practical
applications.
Note added: This work was submitted to PRL as LU9745 on 29 July 2004, and the
decision was returned on 11 November 2004, which advised us to resubmit to some
specialized journal, probably, PRA, after revision. We publish it here in
memory of Prof. Fu-Guo Deng (1975.11.12-2019.1.18), from Beijing Normal
University, who died on Jan 18, 2019 after two years heroic fight with
pancreatic cancer. In this work, we designed a protocol to repeatedly use a
classical one-time-pad key to transmit ciphertext using single photon states.
The essential idea was proposed in November 1982, by Charles H. Bennett, Gilles
Brassard, Seth Breidbart, which was rejected by Fifteenth Annual ACM Symposium
on Theory of Computing, and remained unpublished until 2014, when they
published the article, Quantum Cryptography II: How to re-use a one-time pad
safely even if P=NP, Natural Computing (2014) 13:453-458, DOI
10.1007/s11047-014-9453-6. We worked out this idea independently. This work has
not been published, and was in cooperated into quant-ph 706.3791 (Kai Wen, Fu
Guo Deng, Gui Lu Long, Secure Reusable Base-String in Quantum Key
Distribution), and quant-ph 0711.1642 (Kai Wen, Fu-Guo Deng, Gui Lu Long,
Reusable Vernam Cipher with Quantum Media).Comment: It was submitted to PRL in 2004. We designed a protocol to use
repeatedly a one-time-pad to transmit ciphertext using single photons. The
idea was proposed by Bennett, Brassard, Breidbart in 1982. Unknowing their
work, we rediscovered this idea independently. We publish it here in memory
of Prof. Fu-Guo Deng (1975.11.12-2019.1.18), who died after two years heroic
fight with pancreatic cance
Complete hyperentangled-Bell-state analysis for quantum communication
It is impossible to unambiguously distinguish the four Bell states in
polarization, resorting to linear optical elements only. Recently, the
hyperentangled Bell state, the simultaneous entanglement in more than one
degree of freedom, has been used to assist in the complete Bell-state analysis
of the four Bell states. However, if the additional degree of freedom is
qubitlike, one can only distinguish 7 from the group of 16 states. Here we
present a way to distinguish the hyperentangled Bell states completely with the
help of cross-Kerr nonlinearity. Also, we discuss its application in the
quantum teleportation of a particle in an unknown state in two different
degrees of freedom and in the entanglement swapping of hyperentangled states.
These applications will increase the channel capacity of long-distance quantum
communication.Comment: 9 pages, 6 figure
Water Injection in Longwall Top-coal Caving Face in China
This paper discussed the means of improving dust control efficiency using water injection. At first, the authors point out that internal water has effect on dust control. The objective of water injection is to increase the amount of internal water. Secondly, by analyzing the development trend of crack in top-coal, proper water injection station and boleholes can be determined for dust control
Establishing language skills in Europe: The Inspirations on Chinese Foreign Language Study
In order to promote transparency and coherence for language learning, teaching and especially estimate, Council of Europe(CoE)developed the Common European Framework of Reference(CEFR) and European Language Portfolio(ELP).The CEFR and the ELP are one of the most influential documents of the last decade in the fields of language learning and teaching in Europe and elsewhere. It is therefore also very important for the contacts between Europe and China, in educational contact as well as in professional contexts. Key words: Europe; language Skill; The Common European Framework of Reference; European Language PortfolioRésumé: Afin de promouvoir la transparence et la cohérence pour l'apprentissage, l’enseignement et l’évaluation des langues, le Conseil de l'Europe (CoE) a élaboré le Cadre européen commun de référence (CECR) et le Portfolio européen des langues (PEL). Le CECR et le PEL sont l'un des documents les plus influents de la dernière décennie dans les domaines de l'apprentissage et de l'enseignement des langues en Europe et ailleurs. Il est donc ainsi très important pour les contacts entre l'Europe et la Chine, non seulement dans le contexte pédagogique, mais aussi dans des contextes professionnels.Mots-clés : Europe; compétences linguistiques; Cadre européen commun de référence; Portfolio européen des langue
-fuzzy ideal degrees in effect algebras
summary:In this paper, considering being a completely distributive lattice, we first introduce the concept of -fuzzy ideal degrees in an effect algebra , in symbol . Further, we characterize -fuzzy ideal degrees by cut sets. Then it is shown that an -fuzzy subset in is an -fuzzy ideal if and only if which can be seen as a generalization of fuzzy ideals. Later, we discuss the relations between -fuzzy ideals and cut sets (-nested sets and -nested sets). Finally, we obtain that the -fuzzy ideal degree is an -fuzzy convexity. The morphism between two effect algebras is an -fuzzy convexity-preserving mapping
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