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Building a next generation Internet with source address validation architecture

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Science in china(Series F) 2008年第11期51卷 1681-1691页

作者： WU JianPing1,3,REN Gang1,3 & LI Xing2,3 1 Department of Computer Science,Tsinghua University,beijing 100084,china 2 Department of Electronic Engineering,Tsinghua University,beijing 100084,china 3 Tsinghua National Laboratory for information Science and technology(TNList) ,beijing 100084,china Department of Computer Science Tsinghua University Beijing 100084 China Department of Electronic Engineering Tsinghua University Beijing 100084 China Tsinghua National Laboratory for information Science and technology (TNList) Beijing 100084 China

The IP packet forwarding of current Internet is mainly destination based. In the forwarding process, the source IP address is not checked in most *** causes serious security, management and accounting problems. Based on the drastically increased IPv6 address space, a ＂source address validation architecture＂（SAVA） is proposed in this paper, which can guarantee that every packet received and forwarded holds an authenticated source IP address. The design goals of the architecture are lightweight, loose coupling, ＂multi-fence support＂ and incremental deployment. This paper discusses the design and implementation for the architecture, including inter-AS, intra-AS and local subnet. The performance and scalability of SAVA are described. This architecture is deployed into the CNGI-CERNET2 infrastructure a large-scale native IPv6 backbone network of the china Next Generation Internet project. We believe that the SAVA will help the transition to a new, more secure and dependable Internet.

关键词： IP source address validation network architecture network security

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Combining Digital Watermarks with Two-Color Bitmap Image

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The Journal of china Universities of Posts and Telecommunications 2000年第Z1期 31-35页

作者： SAAD A Amer, YANG Yi-xian (information security center, beijing University of Posts and Telecommunications, beijing 100876, P.R. china)

A technology for combining digital watermarks with two-color bitmap image based on the threshold watermarking method is presented. Our technology doesn’t add any thing to the digital media, but combines the watermarks in two-color bitmap image by looking for some characteristic values in the bitmap and uses the relationship between the watermarks and the characteristic values to prove the copyright protection. The choice of the characteristic values depends on the choice of a cryptographic key known by the owner of the bitmap. The benefit of using a cryptographic key is to combine the watermarks with the bitmap in a high secure way.

关键词： digital watermarks information hiding copyright protection

information content security on the Internet:the control model and its evaluation

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Science china(information Sciences) 2010年第1期53卷 30-49页

作者： FANG BinXing1, GUO YunChuan2,3 & ZHOU Yuan4 1School of Computer, beijing University of Posts and Telecommunications, beijing 100029, china 2Institute of Computing technology, Chinese Academy of Sciences, beijing 100190, china 3Graduate University of Chinese Academy of Sciences, beijing 100049, china 4National Computer Network Emergency Response Technical Team/Coordination center of china, beijing 100029, china 1. School of Computer Beijing University of Posts and Telecommunications Beijing 100029 China2. Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China4. National Computer Network Emergency Response Technical Team/Coordination Center of China Beijing 100029 China

Flooding of harmful information on the Internet seriously endangers the physiological and mental health of teenagers. Due to the user-friendliness of the Internet as well as the difficulty in the authentication for the access of specific categories of information, curbing the transmission of harmful information, i.e., assuring the information content security (ICS), has become a reasonable yet challenging alternative. At present, there is an urgent need to develop a systematic model that can effectively carry out the curbing. In fact, curbing the transmission of harmful information by way of filtering can be modeled by access control. In the paper, based on the three core-elements of communication, namely, "Who communicates with whom", "How do they communicate" and "What is the content of communication", we propose a control model, called ICCON. Unlike the existing access control, the reference monitor (RM) of our model is placed in the transmission channel, and moreover, an evaluation frame is proposed, through which the effectiveness of the RM in controlling information transmission on the Internet can be quantitatively evaluated.

关键词： content security access control quantitative evaluation

Corslet: A shared storage system keeping your data private

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Science china(information Sciences) 2011年第6期54卷 1119-1128页

作者： XUE Wei 1,2 , SHU JiWu 1,2 , LIU Yang 1 & XUE Mao 1 1 Department of Computer Science and technology, Tsinghua University, beijing 100084, china 2 Tsinghua National Laboratory for information Science and technology, Tsinghua University, 1. Department of Computer Science and technology Tsinghua University Beijing 100084 China2. Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China

With the exponential growth of digital data, it is becoming more and more popular to store data in shared distributed storage systems inside the same organization. In such shared distributed storage systems, an ordinary user usually does not have the control permission over the whole system, and thus cannot secure data storage or data sharing of his own files. To solve this issue, this paper proposes a new system architecture to secure file storing and sharing efficiently over untrusted shared storage and network environments. Based on this architecture, this paper designs and implements a stackable secure storage system called Corslet. Corslet can run directly on deployed underlying storage systems without modification, while bringing end-to-end confidentiality and integrity as well as efficient access control for user data. For individual users, Corslet is easy to use, and does not require users to maintain or manage any keys on their client machines locally. The Bonnie++ and IOzone benchmark results show that the throughput of Corslet over NFS can achieve more than 90% of native NFS throughput in most tests, proving that Corslet can provide enhanced security for user data while maintaining acceptable performance.

关键词： storage security access control key management shared file system

Monaural voiced speech segregation based on elaborate harmonic grouping strategies

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Science china(information Sciences) 2011年第12期54卷 2491-2500页

作者： LIU WenJu 1 , ZHANG XueLiang 1 , JIANG Wei 1 , LI Peng 2 & XU Bo 2 1 National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, beijing 100190, china 2 Digital Media Content technology Research center, Institute of Automation, Chinese Academy of Sciences, beijing 100190, china 1. National Laboratory of Pattern Recognition Institute of Automation Chinese Academy of Sciences Beijing 100190 China2. Digital Media Content Technology Research Center Institute of Automation Chinese Academy of Sciences Beijing 100190 China

In this paper, an enhanced algorithm based on several elaborate harmonic grouping strategies for monaural voiced speech segregation is proposed. Main achievements of the proposed algorithm lie in three aspects. Firstly, the algorithm classifies the time-frequency (T-F) units into resolved and unresolved ones by carrier-to-envelope energy ratio, which leads to more accurate classification results than by cross-channel correlation. Secondly, resolved T-F units are grouped together according to minimum amplitude principle, which has been verified to exist in human perception, as well as the harmonic principle. Finally, "enhanced" envelope autocorrelation function is employed to detect amplitude modulation rates, which helps a lot in reducing half-frequency error in grouping of unresolved units. Systematic evaluation and comparison show that performance of separation is greatly improved by the proposed algorithm. Specifically, signal-to-noise ratio (SNR) is improved by 0.96 dB compared with that of previous method. Besides, our algorithm is also effective in improving the PESQ score and subjective perception score.

关键词： computational auditory scene analysis voiced speech separation harmonistic principle minimum amplitude principle elaborate harmonic grouping strategies

Experimental investigation of MIMO relay channels statistics and capacity based on wideband outdoor measurements at 2.35 GHz

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Science china(information Sciences) 2011年第9期54卷 1945-1956页

作者： NIE Xin 1,2,ZHANG JianHua 1,2,LIU ZeMin 1 & ZHANG Ping 1,2 1 Key Laboratory of Universal Wireless Communications,Ministry of Education beijing University of Posts and Telecommunications,beijing 100876,china 2 Wireless technology Innovation Institute,beijing University of Posts and Telecommunications,beijing 100876,china 1. Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China2. Wireless Technology Innovation Institute Beijing University of Posts and Telecommunications Beijing 100876 China

Relay,which serves to enhance the performance of future communication networks,is one of the most promising techniques for IMT-Advanced *** potential performance improvement of relay is investigated in this *** investigation consists of two *** the first step,to obtain a better understanding of the fundamental properties of relay channels,we conducted outdoor measurements at 2.35 GHz with 50 MHz bandwidth in a typical urban area of *** links constituting the relay transmission,i.e.,the link between base station and relay station,the link between relay station and mobile station and the link between base station and mobile station were measured by employing a real-time channel *** main factors that affect the MIMO channel capacity,i.e.,the channel gain and effective degrees of freedom,are *** cross-polarization discrimination was obtained by utilizing space-alternating generalized expectation-maximization *** channel parameters of the three links are statistically analyzed and *** the second step,based on the measured data,the performance of different relaying schemes,i.e.,amplify-and-forward and decode-and-forward,is *** impact of RS antenna configuration on the capacity is also *** measurement and evaluation results reveal that the relay can significantly improve the system coverage and performance.

关键词： MIMO relay channels IMT-Advanced frequency band channel characteristics relay performance evaluation

Influence of Yb^(3+) concentration on the upconversion luminescence of oxyfluoride material doped with Er^(3+)

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 310-314页

作者： ZHAO SuLing1,XU Zheng1,WANG LiHui2 & S. Wageh3 1 Institute of Optoelectronic technology,Key Laboratory of Luminescence and Optical information (beijing Jiaotong University),Ministry of Education,beijing 100044,china 2 Department of Physics,Chinese People’s Public security University,beijing 100038,china 3 Physics & Engineering Mathematics Department Faculty of Electronic Engineering Menufiya University,Menouf 32952,Egypt 1. Institute of Optoelectronic technology Key Laboratory of Luminescence and Optical Information (Beijing Jiaotong University) Ministry of Education Beijing 100044 China2. Department of Physics Chinese People’s Public Security University Beijing 100038 China3. Physics & Engineering Mathematics Department Faculty of Electronic Engineering Menufiya University Menouf 32952 Egypt

In this paper,a new upconversion luminescent material co-doped with Erbium and Ytterbium is reported. The upconversion luminescence transition routes and related properties are studied. The results show that the absorption and emission intensities under excitation of 980 nm laser increase with the increase of the Yb3+ concentration. The red emission is stronger than the green emission. The energy transfer process plays an important role in the upconversion mechanism.

关键词： upconversion luminescence Er3+ Yb3+

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A more efficient accountable authority IBE scheme under the DL assumption

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Science china(information Sciences) 2010年第3期53卷 581-592页

作者： XU Peng, CUI GuoHua, FU Cai & TANG XueMing Laboratory of information security, College of Computer Science, Huazhong University of Science and technology, Wuhan 430074, china 1. Laboratory of information security College of Computer Science Huazhong University of Science and Technology Wuhan 430074 China

In 2007, Goyal introduced a new and creative approach, called accountable authority identity-based encryption (referred to as A-IBE), to reduce the degree of trust that must be placed in the private-key generator (PKG) in an identity-based encryption (IBE) scheme. Based on his work, a new universal A-IBE scheme is proposed in this paper. Compared with Goyal’s universal scheme, this new universal A-IBE scheme not only optimizes the time requirements for pairing operations, but also achieves a "tighter" security reduction based on a weaker hard problem (the discrete logarithm problem) under a stronger security definition (using an adaptively selected identity). Because there are many fewer pairing operations in this new scheme, the performance of the application can be improved to some degree. In addition, because of the "tighter" security reduction achieved by this new proposed scheme, a less restrictive security parameter can be chosen while achieving the same security as with Goyal’s scheme along with an improvement in performance. In the respect of the time requirement, compared with the Goyal’s universal scheme, this new scheme could be more efficient. Regrettably, these improvements will increase the memory needed for the public parameters and the volume of communications required. Compromise values of the public parameters should therefore be chosen to balance the advantages and drawbacks.

关键词： identity-based encryption accountable authority identity-based encryption pairing operation discrete logarithm problem

Model of Current Threshold for Perception in Testing Electrical Safety Performance

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Transactions of Tianjin University 2010年第1期16卷 11-16页

作者：王晓飞张朝晖李东刘国忠赵旭 School of information Engineering University of Science and Technology Beijing School of Electro-Optical Engineering Beijing Information Science and Technology University Department of Neurology The 306th Hospital of PLA

A generalized mathematical model of human body current threshold for perception was established and the current flowing through human body could be arbitrary cyclical *** relationship between human body current threshold for perception and current frequency, true root mean square(RMS) value and influence factor was described.A test system was established based on electroencephalogram(EEG) to study the relationship between human body current threshold for perception and current waveform, frequency ...

关键词： electrical safety performance leakage current current threshold for perception current waveform electroencephalogram(EEG)

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