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A formal model of fair exchange protocols

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Science in china(Series F) 2005年第4期48卷 499-512页

作者： QING Sihan1.2,3 & LI Gaicheng1.2,3 1. engineering {1. center for information security technology, Institute of Software, Chinese Aca- demy of Sciences, beijing 1.0080, china 2. beijing Zhongke Ansheng Corporation of information technology, beijing 1.0080, china 3. Graduate School of the Chinese Academy of Sciences, beijing 1.0039, china 1. engineering {1. center for information security technology Institute of Software Chinese Academy of Sciences 100080 Beijing China 2. beijing Zhongke Ansheng Corporation of {1. technology 100080 Beijing China 3. Graduate School of the Chinese Academy of Sciences 100039 Beijing China

Based on the study of existing fair exchange protocols, this paper sets up an accurate formal model by stepwise refinement. In the process of refinement an unreliable channel is employed to simulate an attack behavior. The model provides a novel formal definition of exchanged items, and presents the formal goals for fairness, accountability, etc., reflecting the inherent requirements for fair exchange protocols across-the-board. In order to check, prove, and design fair exchange protocols effectively and efficiently, the model puts forward a novel property of abuse-freeness which applies to all fair exchange protocols, gives a formal definition for trust strand of the third party, and presents general criteria of designing a secure and effective fair exchange protocol. Taking a typical fair exchange protocol as an example, this paper presents the analysis steps of fair exchange protocols appealing to our model. An unknown attack is uncovered. The analysis reveals the process of a complete attack, discovering deeper reasons for causing an attack. Finally, we modify the flawed protocol and the revised protocol ensures the desirable properties.

关键词： events local causal relation local temporal relation global relation exchanged item security goals.

Identifying heavy hitters in high-speed network monitoring

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Science china({1. Sciences) 2010年第3期53卷 659-676页

作者： ZHANG Yu1, FANG BinXing1,2 & ZHANG YongZheng2 1research center of Computer Network and information security technology, Harbin Institute of technology, Harbin 150001, china 2research center of information security, Institute of Computing technology, Chinese Academy of Sciences, beijing 100190, china 1. research {1. of Computer Network and information security technology Harbin Institute of Technology Harbin 150001 China2. Research Center of Information Security Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China

Identifying heavy hitters in a network traffic stream is important for a variety of network applications ranging from traffic engineering to anomaly detection such as detection of denial-of-service attacks. Existing methods generally examine newly arriving items in the stream, perform a small number of operations using a small amount of memory, and still provide guarantees on the identifying accuracy. In high-speed network monitoring, the update speed per item is extremely critical. However, so far as we know, there are no identifying algorithms which can provide constant update time (O(1.) in a weighted data stream. In this paper, we present an algorithm named Weighted Lossy Counting (WLC) which is able to identify heavy hitters in a high-speed weighted data stream with constant update time. WLC employs a novel efficient partially ordered data structure which is able to provide a fast per-item update speed while keeping the memory cost relatively low. We compare WLC with state-of-the-art algorithms for finding heavy hitters in real traffic traces. The experimental results show that WLC performs well in accuracy (recall, precision and average relative error) as other algorithms; moreover it has a much higher update speed at the cost of relatively larger memory space used. A theoretical worst-case memory bound of WLC is also derived in this paper; however, experiments with long real traffic traces show that WLC requires much less space than the theoretical bound in practice.

关键词： network traffic monitoring heavy hitter weighted data streams

Formal analysis and design of multi-party fair exchange protocols

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Science in china(Series F) 2006年第2期49卷 155-174页

作者： QING Sihan1.2,3 & LI Gaicheng1.3 1. engineering {1. center for information security technology, Institute of Software, Chinese Academy of Sciences, beijing 1.0080, china 2. beijing Zhongke Ansheng Corporation of information technology, beijing 1.0080, china 3. Graduate School of the Chinese Academy of Sciences, beijing 1.0039, china 1. engineering {1. center for information security technology Institute of Software Chinese Academy of Sciences Beijing 100080 China 2. beijing Zhongke Ansheng Corporation of {1. technology Beijing 100080 China 3. Graduate School of the Chinese Academy of Sciences Beijing 100039 China

Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately,

关键词： fair exchange logical protocol formal model security requirement.

A property-based attestation protocol for TCM

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Science china({1. Sciences) 2010年第3期53卷 454-464页

作者： FENG DengGuo1.2 & QIN Yu1.2 1.tate Key Laboratory of information {1., Institute of Software, Chinese Academy of Science, beijing 1.01.0, china 2National engineering research center of information {1., beijing 1.01.0, china 1. State Key Laboratory of information {1. Institute of Software Chinese Academy of Science Beijing 100190 China2. National Engineering Research Center of Information Security Beijing 100190 China

This paper presents a property attestation protocol for the security chip TCM (trusted cryptographic module) via analyzing the problems of the current property attestation, which is built on the property attestation model with the online trust third party. In the protocol the prover utilizes the zero-knowledge proof by the attribute certificates, configuration commitment and TCM signature, and attests its configuration and status which are compliant with the declarative security property. The protocol is characterized by shorter signature length and lower computations. The security of the protocol is proved at the random oracle model. The protocol can help extend application and improve standard for security chip TCM, and it also has practical value and immediate significance.

关键词： trust computing trust cryptographic module (TCM) property attestation signature of knowl- edge configuration commitment

Polynomial analysis of canopy spectra and biochemical component content inversion

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Science china Earth Sciences 2005年第10期48卷 1780-1791页

作者： YAN Chunyan1. LIU Qiang1. NIU Zheng1. WANG Jihua2, HUANG Wenjiang2 & LIU Liangyun 2 1. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and beijing Normal University, beijing 1.01.1. china 2. National engineering research center for information technology in Agriculture, beijing 1.0089, china State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and beijing Normal University beijing china National engineering {1. center for information technology in Agriculture beijing china

A polynomial expression model was developed in this paper to describe directional canopy spectra, and the decomposition of the polynomial expression was used as a tool for re-trieving biochemical component content from canopy multi-angle spectra. First, the basic formula of the polynomial expression was introduced and the physical meaning of its terms and coeffi-cients was discussed. Based on this analysis, a complete polynomial expression model and its decomposition method were given. By decomposing the canopy spectra simulated with SAILH model, it shows that the polynomial expression can not only fit well the canopy spectra, but also show the contribution of every order scattering to the whole reflectance. Taking the first scattering coefficients a1. and a01.for example, the test results show that the polynomial coefficients reflect very well the hot spot phenomenon and the effects of viewing angles, LAI and leaf inclination angle on canopy spectra. By coupling the polynomial expression with leaf model PROSPECT, a canopy biochemical component content inversion model was given. In the simulated test, the canopy multi-angle spectra were simulated by two different models, SAILH and 4-SCALE re-spectively, then the biochemical component content was retrieved by inverting the coupled polynomial expression + PROSPECT model. Results of the simulated test are promising, and when applying the algorithm to measured corn canopy multi-angle spectra, we also get relatively accurate chlorophyll content. It shows that the polynomial analysis provides a new method to get biochemical component content independent of any specific canopy model.

关键词： polynomial expression, canopy spectra, decomposition, biochemical component content, inversion.

Black-box testing based on colorful taint analysis

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Science china({1. Sciences) 2012年第1期55卷 171-183页

作者： CHEN Kai1,2,3,FENG DengGuo1,SU PuRui1&ZHANG YingJun1,2,3 1State Key Laboratory of information security,Institute of Software,Chinese Academy of Science,beijing 100190,china 2State Key Laboratory of information security,Graduate University of Chinese Academy of Sciences,beijing 100049,china 3National engineering research center of information security,beijing 100190,china 1. State Key Laboratory of information {1. Institute of Software Chinese Academy of Science Beijing 100190 China2. State Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China3. National Engineering Research Center of Information Security Beijing 100190 China

Software vulnerability detection is one of the most important methods for guaranteeing software *** main classes of methods can detect vulnerabilities in binary files:white-box testing and black-box *** former needs to construct and solve path constraints to detect *** has two main drawbacks:path exploding and complexity of *** latter often aimlessly exhausts various inputs to test binary *** paper combines both testing methods to detect vulnerabilities in binary *** analyzing the input elements that aect check condition corresponding to a certain check point,we can generate one class of inputs that get to the check point to increase fuzzing *** analyzing the relationship between guard conditions and check condition,the redundant check points are *** taint analysis method(CTAM)is proposed to compute guard conditions,which is more ecient than traditional taint analysis method(TTAM).We implemented a prototype and made several experiments on *** results showed that our method could increase the eciency of black-box testing.

关键词： software testing vulnerability detection dynamic testing black-box testing colorful taint analysis

Distribution,formation and evolution of sand ridges on the East china Sea shelf

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Science china(Technological Sciences) 2010年第3期53卷 822-828页

作者： ZHAO RenBao 1,2,SUN HaiTao 3,WU YaSheng 3 &ZHAO ChuanFeng 1,2 1MOE Key Laboratory of Petroleum engineering,china University of Petroleum,beijing 102249,china 2 Enhanced Oil Recovering research center,china University of Petroleum,beijing 102249,china 3Faculty of Natural Resource&information technology,china University of Petroleum,beijing 102249,china 1. MOE Key Laboratory of Petroleum engineering China University of Petroleum Beijing 102249 China2. Enhanced Oil Recovering Research Center China University of Petroleum Beijing 102249 China3. Faculty of Natural Resource & Information Technology China University of Petroleum Beijing 102249 China

Influence of CO2 corrosion on reservoir mineralogical composition,pore structure and their mechanical characteristics was studied using XRD,SEM,rock tri-axial machine and core flow experimental *** was found that the corrosion effect was mainly attributed to rock texture and structure,fluid composition and external dynamical conditions in the experimental *** cores with bedding structures,their bedding surfaces were the preferential corrosion regions,because micro-cracks would evolve at these surfaces in the pressure-releasing ***,for cores with massive structures controlled by stable water environment,the CO2 corrosion would result in pore enlargement and secondary pore *** gas velocity from outlet showed sharp increase in the injection process of CO2-H2O *** could be explained by two changes caused by *** was the opening and closure of *** other was particle *** the corrosion time increased,both tensile strength and compressive strength decreased,which confirmed decrease of cementation *** should also be noted that permeability increase and micro-cracks generation would pose damage to the capacity of CO2 geological storage.

关键词： carbon dioxide geological storage mineralization enhanced oil recovery corrosion

Spray and forward:Efficient routing based on the Markov location prediction model for DTNs

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Science china({1. Sciences) 2012年第2期55卷 433-440页

作者： DANG Fei1.YANG XiaoLong1.2 & LONG KePing2 1.research {1. for Optical Internet and Mobile information Networks(COIMIN),University of Electronic Science and technology of china,Chengdu 61.731.china 2 School of Computer and Communications engineering,University of Science and technology beijing,beijing 1.0083,china 1. research {1. for Optical Internet and Mobile information Networks (COIMIN) University of Electronic Science and Technology of China Chengdu 611731 China2. School of Computer and Communications Engineering University of Science and Technology Beijing Beijing 100083 China

Typical delay tolerant networks(DTNs)often suffer from long and variable delays,frequent connectivity disruptions,and high bit error *** DTNs,the design of an efficient routing algorithm is one of the key *** existing methods improve the accessibility probability of the data transmission by transmitting many copies of the packet to the network,but they may cause a high network *** address the tradeoff between a successful delivery ratio and the network overhead,we propose a DTN routing algorithm based on the Markov location prediction model,called the spray and forward routing algorithm(SFR).Based on historical information of the nodes,the algorithm uses the second-order Markov forecasting mechanism to predict the location of the destination node,and then forwards the data by greedy routing,which reduces the copies of packets by spraying the packets in a particular *** contrast to a fixed mode where a successful-delivery ratio and routing overhead are contradictory,a hybrid strategy with multi-copy forwarding is able to reduce the copies of the packets efficiently and at the same time maintain an acceptable successful-delivery *** simulation results show that the proposed SFR is efficient enough to provide better network performance than the spray and wait routing algorithm,in scenarios with sparse node density and fast mobility of the nodes.

关键词： delay tolerant networks spray and forward Markov position prediction routing algorithm

Multiparty simultaneous quantum identity authentication with secret sharing

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Science china(Physics,Mechanics & Astronomy) 2008年第3期51卷 321-327页

作者： YANG YuGuang1,2,WEN QiaoYan3 & ZHANG Xing4,5 1 College of Computer Science and technology,beijing University of technology,beijing 100022,china 2 State Key Laboratory of information security (Graduate University of the Chinese Academy of Sciences),beijing 100049,china 3 School of Science,beijing University of Posts and Telecommunications,beijing 100876,china 4 Institute of Electronic technology,information engineering University,Zhengzhou 450004,china 5 Trusted Computing Laboratory,beijing University of technology,beijing 100022,china College of Computer Science technology Beijing University of Technology Beijing 100022 China State Key Laboratory of information {1. [Graduate University of the Chinese Academy of Sciences] Beijing 100049 China School of Science Beijing University of Posts Telecommunications Beijing 100876 China Institute of Electronic technology Information Engineering University Zhengzhou 450004 China Trusted Computing Laboratory Beijing University of Technology Beijing 100022 China

Two multiparty simultaneous quantum identity authentication (MSQIA) protocols based on secret sharing are presented. All the users can be authenticated by a trusted third party (TTP) simultaneously. In the first protocol,the TTP shares a random key K with all the users using quantum secret sharing. The ith share acts as the authentication key of the ith user. When it is necessary to perform MSQIA,the TTP generates a random number R secretly and sends a sequence of single photons encoded with K and R to all the users. According to his share,each user performs the corresponding unitary operations on the single photon sequence sequentially. At last,the TTP can judge whether the impersonator exists. The sec-ond protocol is a modified version with a circular structure. The two protocols can be efficiently used for MSQIA in a network. They are feasible with current technol-ogy.

关键词： quantum identity authentication secret sharing quantum cryptography