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SEVERAL CRYPTOGRAPHIC APPLICATIONS OF ∑-PROTOCOL

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Journal of Systems Science & Complexity 2009年第2期22卷 260-279页

作者： chunming tang Zheng-an YAO School of Mathematics and Information Science Guangzhou University Guangzhou 510006 China State KeyLaboratory of Information Security Institute of Software Science Beijing 100190~ China. School of Mathematics and Computational Sciences Sun Yat-Sen University Guangzhou 510275 China.

∑-protocol has been proved to be a very powerful cryptographic tool and widely used in nnmerous important cryptographic applications. In this paper, the authors make use of ∑-protocol as a main tool to resolve the following difficult problems 1-3 and to construct three ettlcient cryptographic protocols 4 6：1） How to construct a protocol for proving a secret integer to be a Blum integer with form PQ, where P, Q are two different primes and both -- 3（mod 4）;2） How to construct a protocol for proving a secret polynomial with exact degree t - 1 iil a （t, n）- threshold secret sharing scheme：3） How to construct witness indistinguishable and witness hiding protocol not from zero-knowledge proof;4） A publicly verifiable secret sharing scheme with information-theoretic security;5） A delegateable signature scheme under the existence of one-way permutations;6） Non-interactive universal designated verifier signature schemes.

关键词： ∑-protocol Blum integer delegateable signature secret sharing witness hiding protocol,witness indistinguishable protocol universal designated verifier signature.

THE OPTIMAL LINEAR SECRET SHARING SCHEME FOR ANY GIVEN ACCESS STRUCTURE

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Journal of Systems Science & Complexity 2013年第4期26卷 634-649页

作者： tang chunming GAO Shuhong ZHANG Chengli School of Mathematics and Information Science Guangzhou University Key Laboratory of Mathematics and Interdisciplinary Sciences of Guangdong Higher Education Institutes Guangzhou University Department of Mathematical Sciences Clemson University29634U.S.A

Any linear code can be used to construct a linear secret sharing *** this paper,it is shown how to decide optimal linear codes(i.e.,with the biggest information rate)realizing a given access structure over finite *** amounts to solving a system of quadratic equations constructed from the given access structure and the corresponding adversary *** system becomes a linear system for binary *** algorithm is also given for finding the adversary structure for any given access structure.

关键词： Access structure adversary structure cryptography linear code secret sharing.

Monotone Span Program vs. Linear Code

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Chinese Journal of Electronics 2016年第6期25卷 991-998页

作者： tang chunming CHEN Yuenai GAO Xuhong School of Mathematics and Information Sciences Guangzhou University Key Laboratory of Mathematics and Interdisciplinary Sciences of Guangdong Higher Education Institutes Guangzhou University Department of Mathematical Sciences Clemson University

Monotone span program(MSP) and Linear code(LC) are efficient tools to construct Linear secret sharing scheme(LSSS) for a given access structure. Since the size of an MSP or the length of an LC corresponds to the communicational complexity of an LSSS, one main motivation to study MSPs or LCs is the lower bound for their sizes or lengths. Therefore, it is one of the most important open problems how to efficiently construct an MSP or LC for a given access structure Γ with the smallest sizes or shortest length. Our contributions are: We extend tang et al.’s result, showing that, for any given access structureΓ, there exists an MSP or an LC to realize Γ if and only if a system of quadratic equations has solutions; We utilize the relationship between LCs and MSPs to obtain the greatest lower bound on the row size and the column size of MSPs realizing a given Γ, as well as an upper bound on the column size of MSPs; We give an algorithm to construct an MSP with the smallest sizes.

关键词： Cryptography Secret sharing scheme Monotone span program Linear code Size

Cryptography on twisted Edwards curves over local fields

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Science China(Information Sciences) 2015年第1期58卷 150-164页

作者： tang chunming XU MaoZhi QI YanFeng School of Mathematics and Information China West Normal University Laboratory of Mathematics and Applied Mathematics School of Mathematical SciencesPeking University School of Science Hangzhou Dianzi University

Twisted Edwards curves over finite fields have attracted great interest for their efficient and unified addition formula. In this paper, we consider twisted Edwards curves over local fields and introduce a cryptosystem based on quotient groups of twisted Edwards curves over local fields. From the study of formal groups of twisted Edwards curves and twisted Edwards curves over local fields, we give the choice of cryptographic *** element in these groups can be uniformly represented by two n digit p-adic numbers, whereas an element in the elliptic curves in Weierstrass form over local fields is represented by a 3n-2 digit p-adic number and a4n-3 digit p-adic number. In the cryptography on elliptic curves in Weierstrass form over local fields, five cases for different input point pairs in computing points addition have to be considered and sometimes points have to be lifted. In the cryptography on twisted Edwards curves over local fields, the addition formula is simple,unified, and complete, which is efficient, does not need lifting points, and is against the side channel ***, a speedy point multiplication algorithm and some concrete instances are given.

关键词： local fields formal groups elliptic curve cryptography twisted Edwards curves addition law

A strongly secure identity-based authenticated group key exchange protocol

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Science China(Information Sciences) 2015年第9期58卷 98-109页

作者： TENG JiKai WU ChuanKun tang chunming TIAN YouLiang State Key Laboratory of Information Security Institute of Information Engineering Chinese Academy of Sciences School of Mathematics and Information Science Guangzhou University

In group key exchange(GKE) protocols, a shared secret key is established among a group of members for cryptographic use over a public network. An identity-based protocol is preferred to that under the employment of traditional public key infrastructure(PKI), since identity-based cryptosystem can simplify public key management procedure. In ASIACCS 2011, a security model for GKE protocol called EGBG model was proposed. The EGBG model takes ephemeral secret key leakage attack into consideration. Until now, there is no ID-based GKE protocol secure in the EGBG model. In this paper, we propose an identity-based GKE protocol. Its AKE-security with KCIR and full forward secrecy, MA-security with KCIR and its contributiveness are proven in the EGBG model. The proposed protocol does not involve NAXOS trick, which does not resist side channel attack and thus it provides stronger security guarantee. It achieves mutual authentication without applying signature, which makes the protocol more practical.

关键词： identity-based cryptography group key exchange provable security insider security

An Improved Identity-Based Society Oriented Signature Scheme with Anonymous Signers

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Wuhan University Journal of Natural Sciences 2007年第1期12卷 121-125页

作者： tang chunming School of Mathematics and Information Sciences/ Guangdong Province Key Laboratory Institute of Information Security Guangzhou University Guangzhou 510006 Guangdong China

In this paper, we present an improved identity-based society oriented signature scheme with anonymous signers, which satisfies：（1） when members leave or join an organization, the public verification key and the signature verification procedure are unchanged; （2） a user participates in several organizations at the same time, her secret key is only related with her identity. However, no previous schemes have these two properties.

关键词： signature identity-based society oriented signature

Delegateable signatures based on non-interactive witness indistinguishable and non-interactive witness hiding proofs

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Science in China(Series F) 2008年第2期51卷 128-144页

作者： tang chunming PEI DingYi WANG XiaoFeng LIU ZhuoJun Province Key Laboratory Institute of Information Security of Guangzhou University Guangzhou 510006 China State Key Laboratory of Information Security Chinese Academy of Sciences Beijing 100080China School of Mathematics and Computational Mathematics of Shenzhen University Shenzhen 518060 China Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

A delegateable signature scheme （DSS） which was first introduced by Barak is mainly based on the non-interactive zero-knowledge proof （NIZK） for preventing the signing verifier from telling which witness （i.e., restricted subset） is being used. However, the scheme is not significantly efficient due to the difficulty of constructing NIZK. We first show that a non-interactive witness indistinguishable （NlWl） proof system and a non-interactive witness hiding （NIWH） proof system are easier and more efficient proof models than NIZK in some cases. Furthermore, the witnesses em- ployed in these two protocols （NlWl and NIWT） cannot also be distinguished by the verifiers. Combined with the E-protocol, we then construct NlWl and NIWH proofs for any NP statement under the existence of one-way functions and show that each proof is different from those under the existence of trapdoor permutations, Finally, based on our NlWl and NIWH proofs, we construct delegateable signature schemes under the existence of one-way functions, which are more efficient than Barak＇s scheme under the existence of trapdoor permutations.

关键词： delegateable signature non-interactive zero-knowledge non-interactive witness indistinguishable non-interactive witness hiding,∑-protocol

Implementing optimized pairings with elliptic nets

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Science China(Information Sciences) 2014年第5期57卷 137-146页

作者： tang chunming NI DongMei XU MaoZhi GUO BaoAn QI YanFeng School of Mathematics and Information China West Normal University LMAM Chinese Ministry of Education Peking University School of Mathematical Sciences Peking University

In this paper,we use elliptic nets to implement the optimized Ate pairings and optimal pairings on the Barreto-Naehrig curves with embedding degree *** order to do the arithmetic of elliptic curves over finite fields with elliptic nets,we first give some basic properties of elliptic nets associated to elliptic curves over finite fields and the expression of Miller function in terms of elliptic *** we give formulae to compute some optimized pairings with elliptic nets,which is a new method to implement *** method with elliptic nets has time complexity comparable to Miller’s algorithm and it can be optimized.

关键词： elliptic curves elliptic nets pairings Miller’s algorithm pairing-based cryptography

Synthesis of mordenite by solvent-free method and its application in the dimethyl ether carbonylation reaction

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Chinese Journal of Chemical Engineering 2024年第2期66卷 216-223页

作者： Yinghui Liu Shaoduo Liu Xiaosheng Wang Hongjing Wang Ranjia Li Changchun Yu chunming Xu Yuxiang Liu Zhengqiu Xie Yongqiang Wang Pan tang State Key Laboratory of Heavy Oil Processing College of New Energy and MaterialsChina University of Petroleum-BeijingBeijing 102249China Synfuels China Technology Co. LtdBeijing 101400China College of Chemical Engineering Qingdao University of Science&TechnologyQingdao 266042China Yueyang Jucheng Chemical Co. LtdYueyang 414009China

Mordenite with different Si/Al ratios were synthesized by solvent-free method and used for dimethyl ether(DME)carbonylation *** influence of Si/Al ratio in the feedstock on the structure,porosity and acid sites were systematically *** characterization results showed that with the increase of Si/Al ratio in the feedstock,part of silicon species fail to enter the skeleton and the specific surface area and pore volume of the samples *** amount of weak acid and medium strong acid decreased alongside with the increasing Si/Al ratio,and the amount of strong acid slightly *** Al atoms preferentially enter the strong acid sites in the 8 member ring(MR)channel during the crystallization *** high Si/Al ratio sample had more acid sites located in the 8 MR channel,leading to more active sites for carbonylation reaction and higher catalytic *** increasing the Si/Al ratio was beneficial for the improvement of carbonylation reaction activity over the mordenite(MOR)catalyst.

关键词： Carbonylation Dimethyl ether Solvent-free Zeolite Synthesis Catalysis