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Linearly time-varying channel estimation and training power allocation for OFDM/MIMO systems using superimposed training

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science china({2. sciences) 2011年第7期54卷 1456-1470页

作者： zhang Han 1,DAI XianHua 2.& Pan DaRu 1 1 school of Physics and Telecommunication Engineering,South{2. Normal university,guangzhou 510006,china 2.Department of information science and technology,SUN yat-sen university,guangzhou 51002.,china 1. school of Physics and Telecommunication Engineering South China Normal University Guangzhou 510006 China2. Department of Information Science and Technology SUN Yat-sen University Guangzhou 510026 China

We address the problem of estimating the linearly time-varying (LTV) channel of orthogonal frequency division multiplexing (OFDM)/multiple-input multiple-output (MIMO) systems using superimposed training (ST).The LTV channel is modeled by truncated discrete Fourier *** on this model,a two-step approach is adopted to estimate the LTV channel over multiple OFDM *** also present performance analysis of the channel estimation and derive a closed-form expression for the channel estimation *** is shown that the estimation variances,unlike that of the conventional ST-based schemes,approach to a fixed lower-bound as the training length increases,which is directly proportional to information-pilot power *** wireless communication systems with a limited transmission power,we optimize the ST power allocation by maximizing the lower bound of the average channel *** results show that the proposed approach outperforms the frequency-division multiplexed training schemes.

关键词： OFDM/MIMO systems linearly time-varying channel estimation superimposed training training power allocation

A Deniable Authenticated Key Agreement Protocol

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Wuhan university Journal of Natural sciences 2008年第6期13卷 645-650页

作者： TIAN Haibo1,2. CHEN Xiaofeng1,2. zhang fangguo1,2. WEI Baodian1,{2.. school of information science and technology, Sun yat-sen university, guangzhou 510006, Guangdong, china 2. Guangdong Key Laboratory of information Security technology, Sun yat-sen university, guangzhou 5102.5, Guangdong, china school of information {2. and technology Sun Yat-Sen University Guangzhou 510006 Guangdong China Guangdong Key Laboratory of information Security technology Sun Yat-Sen University Guangzhou 510275 Guangdong China

This paper presents a deniable authenticated key agreement protocol. This protocol can provide an authenticated session key while the sender and the receiver can deny their involvement in such a protocol if the protocol is executed successfully. Then both can deny their transmitted messages protected by the authenticated session key. If this protocol fails, no authenticated session key can be established and no protected messages can be transmitted. The protocol can be proved secure against key compromise impersonation attack. The protocol employs a new method to isolate a session key from confirmation keys.

关键词： deniable authentication key agreement key compromise impersonation

RING PROXY SIGNATURES

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Journal of Electronics(china) 2008年第1期25卷 108-114页

作者： Wei Baodian zhang fangguo Chen Xiaofeng Department of Electronics and Communication Engineering Sun Yat-Sen University Guangzhou 510275 China Department of Computer science Sun Yat-Sen University Guangzhou 510275 China Guangdong.Key Laboratory of information Security technology Guangzhou 510275 China

Proxy signatures have been used to enable the transfer of digital signing power within some context and ring signatures can be used to provide the anonymity of a signer. By combining the functionalities of proxy signatures and ring signatures, this paper introduces a new concept, named ring proxy signature, which is a proxy signature generated by an anonymous member from a set of potential signers. The paper also constructs the first concrete ring proxy signature scheme based on the provably secure Schnorr's signatures and two ID-based ring proxy signature schemes. The security analysis is provided as well.

关键词： Proxy signature Ring signature Ring proxy signature ID-based cryptography Bilinear parings

OBLIVIOUS TRANSFER WITH ACCESS CONTROL AND IDENTITY-BASED ENCRYPTION WITH ANONYMOUS KEY ISSUING

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Journal of Electronics(china) 2011年第Z1期 571-579页

作者： Xu Lingling* zhang fangguo* Wen Yamin* ** *({2. of information science and technology,Sun yat-sen university,guangzhou 5102.5,china) **({2. of Mathematics and Computational science,Guangdong university of Business Studies,guangzhou 51032.,china)

In ACM’CCS 2.09,Camenisch,et *** the Oblivious Transfer with Access Control(AC-OT) in which each item is associated with an attribute set and can only be available,on request,to the users who have all the attributes in the associated ***,AC-OT achieves access control policy for conjunction of ***,the functionality of AC-OT is equivalent to the sim-plified version that we call AC-OT-SV:for each item,one attribute is associated with it,and it is requested that only the users who possess the associated attribute can obtain the item by *** one hand,AC-OT-SV is a special case of AC-OT when there is just one associated attribute with each *** the other hand,any AC-OT can be realized by an *** this paper,we first present a concrete AC-OT-SV protocol which is proved to be secure in the model defined by Camenisch,et al..Then from the protocol,interestingly,a concrete Identity-Based Encryption(IBE) with Anonymous Key Issuing(AKI) is given which is just a direct application to *** comparison,we show that the AKI protocol we present is more efficient in communications than that proposed by Chow.

关键词： Oblivious Transfer(OT) Access Control(AC) Identity-Based Encryption(IBE) Anonymous Key Issuing(AKI)

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全域哈希椭圆曲线签名

中国科学：信息科学 2024年第8期54卷 1860-1870页

作者：张方国中山大学计算机学院广州510006 广东省信息安全技术重点实验室广州510006

椭圆曲线密码体制(elliptic curve cryptosystem,ECC)依然是当前应用最广泛的公钥密码体制,其安全核心是椭圆曲线离散对数问题.本文提出了椭圆曲线离散对数的强不动点问题.利用强不动点假设,在随机预言模型下证明了ECDSA(elliptic curve... 详细信息

椭圆曲线密码体制(elliptic curve cryptosystem,ECC)依然是当前应用最广泛的公钥密码体制,其安全核心是椭圆曲线离散对数问题.本文提出了椭圆曲线离散对数的强不动点问题.利用强不动点假设,在随机预言模型下证明了ECDSA(elliptic curvedigital signature algorithm)的一个全域哈希变形方案是可以抵抗自适应选择消息下的存在伪造的签名的聚合性质使得签名方案在诸如区块链、云存储等众多场景中发挥着重要作用,所以本文也讨论了这个全域哈希椭圆曲线签名方案的聚合性质.

关键词：椭圆曲线数字签名不动点加和多项式聚合签名

NEW ID-BASED GROUP SIGNATURE FROM PAIRINGS

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Journal of Electronics(china) 2006年第6期23卷 892-900页

作者： Chen Xiaofeng zhang fangguo Kwangjo Kim school of information {2. and technology Sun Yat-sen University Guangzhou 510275 China International Research Center for information Security Information and Communications University Taejon 305-714 Korea

We argue that traditional identity-based systems from pairings seem unsuitable for designing group signature schemes due to the problem of key escrow. In this paper we first propose new ID-based public key systems without trusted PKG (Private Key Generator) from bilinear pairings. In our new ID-based systems, if the dishonest PKG impersonates an honest user to communicate with others, the user can provide a proof of treachery of the PKG afterwards, which is similar to certificate-based systems. Therefore, our systems reach the Girault’s trusted level 3. We then propose a group signature scheme under the new ID-based systems, the security and performance of which rely on the new systems. The size of the group public key and the length of the signature are independent on the numbers of the group.

关键词： Group signature Bilinear pairings Identity-based cryptography

梯度神经网络求解Sylvester方程之MATLAB仿真

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系统仿真学报 2009年第13期21卷 4028-4031,4037页

作者：张雨浓杨逸文陈轲蔡炳煌中山大学信息科学与技术学院广州510275 中山大学软件学院广州510275

近年来,国内外学者发表了许多关于线性代数问题实时求解的方法,其中包括了矩阵求逆和线性方程组的并行求解方法。在研究了基于梯度法的递归神经网络用于Sylvester矩阵方程的实时求解后,通过使用Kronecker乘积和矩阵向量化等技术进行了MA... 详细信息

近年来,国内外学者发表了许多关于线性代数问题实时求解的方法,其中包括了矩阵求逆和线性方程组的并行求解方法。在研究了基于梯度法的递归神经网络用于Sylvester矩阵方程的实时求解后,通过使用Kronecker乘积和矩阵向量化等技术进行了MATLAB仿真从而验证了相关理论分析。计算机仿真的结果证实了这类神经网络方法在解决Sylvester矩阵方程中的有效性和高效率(特别是在使用幂S型激励函数的情况下)。

关键词：基于梯度法的递归神经网络 Sylvester方程 Kronecker乘积向量化 MATLAB仿真

Study on chromatographic fingerprint of sarcandra glabra (Thunb.) by microwave-assisted extraction coupled to HPLC/DAD

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Journal of Pharmaceutical Analysis 2010年第4期22卷 211-217页

作者： Zhuo-Min zhang1,Zong-Ning Guo1,Gui-Hua Ruan1,2.Jian-Chao Deng1,Xiao-Hua Xiao1,Gong-Ke Li11.school of Chemistry and Chemical Engineering,Sun {2.-sen university,guangzhou 5102.5 2.Department of Material and Chemistry,Guilin university of technology,Guilin 541004,china school of Chemistry and Chemical Engineering Sun Yat-sen University Guangzhou 510275 China Department of Material and Chemistry Guilin University of Technology Guilin 541004 China

Microwave-assisted extraction(MAE)was used for extraction of effective components of sarcandra glabra(Thunb.),and then chromatographic fingerprint of sarcandra glabra(Thunb.)was studied by high performance liquid chromatography/diode array detector(HPLC/DAD).The conditions of MAE were optimized by an orthogonal experiment,and then the authentication and validation of the chromatographic fingerprint were *** peaks were identified as common peaks in the fingerprint chromatograms,and isofraxidin was considered as a reference compound and *** standard deviations of retention time and peak area of each component were less than 3% and 8%,*** and difference analysis were conducted by use of PCA and relation *** batches of sarcandra glabra(Thunb.)samples from two different producing areas could be classified into two different groups in the PCA *** results showed that MAE-HPLC/DAD method was simple,efficient and stable for the study of complex chromatographic fingerprint of sarcandra glabra(Thunb.),which could provide more reliable and precise information for quality evaluation.

关键词： chromatographic fingerprint sarcandra glabra(thunb.) microwave-assisted extraction high performance liquid chromatography/diode array detector

zhang Dynamics with Modified Error-Functions for Online Solution of Nonlinear Equations so as to Avoid Local Minima

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Zhang Dynamics with Modified Error-Functions for Online Solu...