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CMQV+:An authenticated key exchange protocol from CMQV

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Science china(Information Sciences) 2012年第7期55卷 1666-1674页

作者： LI Hui 1,2.& WU ChuanKun 1 1 State Key Laboratory of Information Security,Institute of Software,Chinese Academy of Sciences,beijing 100190,china {2. university of Chinese Academy of Sciences,beijing 100049,china State Key Laboratory of Information Security Institute of Software Chinese Academy of Sciences Beijing China graduate university of Chinese Academy of Sciences Beijing China

Ustaoglu presents a secure and efficient key exchange protocol named CMQV,based on the design rationales of HMQV and *** with the latter two protocols,on one hand,CMQV achieves high performance of HMQV,and on the other,it is proven secure in eCK model as NAXOS ***,CMQV enjoys the security proof under gap Diffie-Hellman assumption as indicated by its *** this paper,we propose a variant of CMQV,called CMQV+,which is proven secure under a weaker assumption (*** Diffie-Hellman assumption) in eCK model with random oracles while maintaining the high-performance feature of CMQV as much as possible.

关键词： key exchange eCK model trapdoor-test technique provable security CDH assumption

CH_4 uptake flux of Leymus chinensis steppe during rapid growth season in Inner Mongolia,china

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Science china Earth Sciences 2010年第7期53卷 977-983页

作者： GENG YuanBo1, LUO GuangQiang1,2.& YUAN GuoFu1 1 Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, beijing 100101, china {2. university of Chinese Academy of Sciences, beijing 100049, china Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China graduate university of Chinese Academy of Sciences Beijing China

The influence of near ground atmosphere CH4 concentration, soil water content, soil Eh, plants, soil temperature, and pH on CH4 uptake flux of Leymus chinensis steppe during rapid growth season was studied using field in-situ measurement in Xilin River basin of Inner Mongolia, china. The results showed that CH4 uptake flux was positively correlated with near ground atmosphere CH4 concentration and soil Eh but negatively correlated with soil water content. Precipitation may decrease the CH4 flux by increasing the soil water content. The average fluxes of three treatments during the observation period were 1.52.(natural conditions, 1.51 (aboveground plants were excluded), and 2.00 mg m?2.d?1 (all plants were removed), respectively. The difference between the CH4 flux of natural condition treatment and that of removing aboveground plants treatment is small, whereas the flux of removing all plants treatment is larger than the other two treatments. This means that the contribution of aboveground plants to CH4 uptake flux is smaller than that of roots or roots-removing process. CH4 uptake flux is not sensitive to soil temperature and the narrow-ranged soil pH (6.36–7.86). The Leymus chinensis steppe acts as a sink for CH4, and thus more studies should be focused on its affecting factors and related mechanisms.

关键词： CH4 uptake flux Leymus chinensis steppe affecting factors static opaque chamber/gas chromatography method

A two-round honest-verifier zero-knowledge protocol

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Science china(Information Sciences) 2010年第5期53卷 954-963页

作者： LIU HanWu 1,2.& LIN DongDai 1 1 The State Key Laboratory of Information Security, Institute of Software, Chinese Academy of Sciences, beijing 100190, china {2. university of the Chinese Academy of Sciences, beijing 100049, china The State Key Laboratory of Information Security Institute of Software Chinese Academy of Sciences Beijing China graduate university of the Chinese Academy of Sciences Beijing China

Since the concept of zero-knowledge protocols was introduced, it has attracted a lot of attention and in turn showed significant effect on the development of cryptography, complexity theory and other areas. The round complexity of a zero-knowledge protocol is a very important efficiency consideration, and it is required to be as small as possible. Generally, it is desirable to have zero-knowledge protocols with constant numbers of rounds. Goldreich and Oren proved that only languages in BPP have one-round and two-round zero-knowledge protocols. Moreover, they also showed that only languages in BPP have one-round honest-verifier zero-knowledge protocols. The notion of honest-verifier zero-knowledge protocols is highly non-trivial and fascinating itself, and has many other uses. Thus, the problem as to whether there exist two-round honest-verifier zero-knowledge protocols becomes an important open problem. In this paper, we introduce a new simulation technique and present a two-round honest-verifier zero-knowledge protocol for any language in N P under a standard complexity assumption based on this technique.

关键词： proof system argument system zero-knowledge witness indistinguishability black-box one-way permutation commitment scheme zap

Dynamic tree-based authenticated group key exchange protocol

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Science china(Information Sciences) 2010年第8期53卷 1591-1602页

作者： LI Hui 1,2., WU ChuanKun 1 & TENG JiKai 1,2.1 State Key Laboratory of Information Security, Institute of Software, Chinese Academy of Sciences, beijing 100190, china {2. university of Chinese Academy of Sciences, beijing 100049, china State Key Laboratory of Information Security Institute of Software Chinese Academy of Sciences Beijing China graduate university of Chinese Academy of Sciences Beijing China

Authenticated group key exchange protocols allow a group of users over a public network to establish a shared secret key for the subsequent cryptographic goals. In this paper, we extend BD-II scheme into a dynamic setting, and propose a tree-based authenticated key exchange protocol which is more suitable for dynamic groups in such as ad hoc networks. Our protocol is proven secure in random-oracle model. Additionally, we analyze the costs of our protocols in both communication and computation terms, and compare its performance with three well-known protocols.

关键词： tree-based group key exchange dynamic provable security

Debris Flow Hazard Assessment Based on Support Vector Machine

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Wuhan university Journal of Natural Sciences 2006年第4期11卷 897-900页

作者： YUAN Lifeng 1, 2., ZHANG Youshui 3 1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, china 2. graduate {2. of Chinese Academy of Sciences, beijing 100049, china 3. Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, beijing 100101, china Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu Sichuan China graduate university of Chinese Academy of Sciences Beijing China Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China

Seven factors, including the maximum volume of once flow , occurrence frequency of debris flow , watershed area , main channel length , watershed relative height difference , valley incision density and the length ratio of sediment supplement are chosen as evaluation factors of debris flow hazard degree. Using support vector machine （SVM） theory, we selected 2.9 basic data of 37 debris flow channels in Yunnan Province as learning samples in this study. We create a debris flow hazard assessment model based on SVM. The model was validated though instance applications and showed encouraging results.

关键词： debris flow hazard assessment support vector machine (SVM)

Characteristics and geological significance of olivine xenocrysts in Cenozoic volcanic rocks from western Qinling

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Progress in Natural Science:Materials International 2006年第12期16卷 1300-1306页

作者： SU Benxun~ 1,2.**, ZHANG Hongfu~1, XIAO Yan~ 1,2.and ZHAO Xinmiao~ 1,2.(1. State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, beijing 10002., china 2. {2. School of Chinese Academy of Sciences, beijing 100039, china) State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China graduate School of Chinese Academy of Sciences Beijing 100039 China

Cenozoic volcanic rocks from the Haoti, Dangchang County of the western Qinling Mountains, contain a few clearly-zoned olivines. These olivines are relatively big in grain sizes and usually have cracks or broken features. Their cores have similar compositions （Mg#=90.4-91.0） to those for the peridotitic xenoliths entrained in host volcanic rocks and their rims are close to the compositions of olivine phenocrysts （Mg#=85.5-81.9）. The CaO contents in these zoned olivines are lower than 0.1%. These features demonstrate that the clearly-zoned olivines are xenocrysts and disaggregated from mantle peridotites. The zoned texture was the result of the interaction between the olivine and host magma. Available data show that the volcanic rocks would have been derived from the mantle source metasomatized by subducted hydrathermally-altered oceanic crust. The formation of these Cenozoic volcanic rocks was perhaps related to the rapid uplift of the Tibetan Plateau.

关键词： Western Qinling Dangchang Haoti Cenozoic volcanic rocks olivine xenocrysts zoned texture.

Electric-stimulus rate encoding algorithm of Mandarin tonal information in cochlear implant

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Progress in Natural Science:Materials International 2006年第12期16卷 1315-1321页

作者： GUAN Tian~1, GONG Qin~1 and YE Datian~2.*(1. Department of Biomedical Engineering, Tsinghua university, beijing 100084, {2. 2. Research Center of Biomedical Engineering, graduate School at Shenzhen, Tsinghua university, Shenzhen 518055, {2.) Department of Biomedical Engineering Tsinghua University Beijing 100084 China Research Center of Biomedical Engineering graduate School Shenzhen Tsinghua University Shenzhen 518055 China

The modern multi-channel cochlear implants usually extract and encode the temporal envelope cues. This kind of algorithms can hardly satisfy the users who speak tonal languages, such as Mandarin. Many studies have tried to enhance the recognition ability of Mandarin through encoding tonal information and made suggestions to frequency-modulate the fixed pulse-rate carrier with the extracted tonal information based on the rate-pitch theory in electric hearing. However, how to encode and deliver the tonal information such as F_0by changing electric-stimulus rate has not got further study in clinical electric-stimulus mode. The present paper focuses on this matter by piecewise calculating the appreciable electric-stimulus rates. Then an electric-stimulus encoding algorithm of Mandarin tone is brought forward and testified through acoustic simulations. Such conclusion can be drawn that this algorithm of electric-stimulus rate could convey tonal information well and help to enhance the Mandarin speech recognition ability.

关键词： cochlear implant tone fundamental frequency electric-stimulus rate.

Direct CP violation in hadronic B decays

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Science china(Physics,Mechanics & Astronomy) 2006年第3期49卷 357-366页

作者： HONG Bihai1,2.& Lü Caidian3 1. Department of Physics, Lishui university, Lishui 32.000,china 2. Department of Physics, Shanghai Jiaotong university, Shanghai 2.0030, china 3. Institute of High Energy Physics, beijing 100049,china Department of Physics Lishui University Lishui China Department of Physics Shanghai Jiaotong University Shanghai China Institute of High Energy Physics Beijing China

There are different approaches for the hadronic B decay calculations, recently. In this paper, we upgrade three of them, namely factorization, QCD factorization and the perturbative QCD approach based on kT factorization, using new parameters and full wave functions. Although they get similar results for many of the branching ratios, the direct CP asymmetries predicted by them are different, which can be tested by recent experimental measurements of B factories.

关键词： CP violation hadronic B decay factorization.

Estimating possible impact of human activity on the warm season temperature in beijing since the industrial era

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Chinese Science Bulletin 2010年第16期55卷 1590-1593页

作者： QIN Li1,2.& ZHOU Xin1,2.1 Institute of Geology and Geophysics,Chinese Academy of Sciences,beijing 10002.,china {2. university of Chinese Academy of Sciences,beijing 100049,china Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China graduate university of Chinese Academy of Sciences Beijing China

Global surface temperature shows an increasing trend over the past 100 *** and natural factors have been invoked to explain this warming, but their relative contribution and the spatial variability remain *** on a 2.50-year temperature record from a stalagmite near beijing, we explore the possible impacts of human activity on the warm season temperature in beijing since the industrial era using the method of singular spectrum analysis (SSA).The results suggest that the warm season temperature in beijing under the natural forcing should have an overall decreasing trend for the past 130 years (1870 to 2.00 AD) with an amplitude of 0.45±0.84°C, while the instrumental record and stalagmite data show an increase of 1.08°*** imply that human activity would have caused an increase in the warm season temperature of beijing for about 1.53±0.84°C compared to its natural trends, from 1870 AD to 2.00 *** results also suggest that anthropogenic forcing began to significantly influence the temperature since 1870 AD, and the effect further intensified since 1915 AD.

关键词：人类活动北京温度工业时代季节温暖估计地表气温