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Study on complicated solid modeling and Cartesian grid generation method

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Science China(Technological Sciences) 2014年第3期57卷 630-636页

作者： QIN Qiang hu changzhen MA TianBao School of Computer Science and Technology Beijing Institute of Technology School of Software Beijing Institute of Technology State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology

A Cartesian grid generation method is developed in this *** kinds of solid modeling methods,CSG and STL models,are used for complicated solid *** staircase boundary approximation is implemented to handle irregular geometries and the computational domain is discretized using a regular Cartesian *** the edge-based integral slice algorithm,the models are sliced with a set of parallel planes to generate 2D slices *** scan line filling technique is used to achieve grid generation after *** grid generation examples with a CSG model and a STL model are given to test the capability of the grid generation *** grid displaying,a method is proposed to remove the hidden surfaces fasten based on the topology of orthogonal hexahedral *** parallelization of grid displaying is achieved by employing multi-threaded parallel *** test results show that the parallel algorithm has the absolute advantage on speed compared to the serial algorithm.

关键词： solid modeling grid generation Cartesian grid staircase boundary treatment

A Concurrent Security Monitoring Method for Virtualization Environments

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China Communications 2016年第1期13卷 113-123页

作者： TIAN Donghai JIA Xiaoqi CHEN Junhua hu changzhen Beijing Key Laboratory of Software Security Engineering Technique School of SoftwareBeijing Institute of Technology State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of Sciences Key Laboratory of IOT Application Technology of Universities in Yunnan Province Yunnan Minzu University

Recently,virtualization technologies have been widely used in *** order to monitor the security of target systems in virtualization environments,conventional methods usually put the security monitoring mechanism into the normal functionality of the target ***,these methods are either prone to be tempered by attackers or introduce considerable performance overhead for target *** address these problems,in this paper,we present a concurrent security monitoring method which decouples traditional serial mechanisms,including security event collector and analyzer,into two concurrent *** one hand,we utilize the SIM framework to deploy the event collector into the target virtual *** the other hand,we combine the virtualization technology and multi-core technology to put the event analyzer into a trusted execution *** address the synchronization problem between these two concurrent components,we make use of Lamport's ring buffer *** on the Xen hypervisor,we have implemented a prototype system named *** experimental results show that COMO can monitor the security of the target virtual machine concurrently within a little performance overhead.

关键词： security virtualization technology concurrent monitoring

An Improved ID-Based Group Key Agreement Protocol

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Tsinghua Science and Technology 2014年第5期19卷 421-428页

作者： Kangwen hu Jingfeng Xue changzhen hu Rui Ma Zhiqiang Li School of Software Beijing Institute of Technology

ID-based constant-round group key agreement protocols are efficient in both computation and communication, but previous protocols did not provide valid message authentication. An improvement based on attack analysis is proposed in this paper. The improved method takes full advantage of the data transmitted at various stages of the protocol. By guaranteeing the freshness of authentication messages, the authenticity of the generator of authentication messages, and the completeness of the authenticator, the improved protocol can resist various passive and active attacks. The forward secrecy of the improved protocol is proved under a Katz-Yung （KY） model. Compared with existing methods, the improved protocol is more effective and applicable.

关键词： group key agreement protocol ID forward secrecy nonsuper-singular elliptic curve

Semi-valid Fuzz Testing Case Generation for Stateful Network Protocol

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Tsinghua Science and Technology 2017年第5期22卷 458-468页

作者： Rui Ma Shuaimin Ren Ke Ma changzhen hu Jingfeng Xue the Beiiing Key Laboratory of Software Security Engineering Technology School of SoftwareBeijing Institute of TechnologyBering 100081China the Internet Center Institute of Communication Standard Research.China Academy of Information and Communication TechnologyBering 100191China

Network protocols are divided into stateless and stateful. Stateful network protocols have complex communication interactions and state transitions. However, the existing network protocol fuzzing does not support state transitions very well. This paper focuses on this issue and proposes the Semi-valid Fuzzing for the Stateful Network Protocol （SFSNP）. The SFSNP analyzes protocol interactions and builds an extended finite state machine with a path marker for the network protocol; then it obtains test sequences of the extended finite state machine, and further performs the mutation operation using the semi-valid algorithm for each state transition in the test sequences; finally, it obtains fuzzing sequences. Moreover, because different test sequences may have the same state transitions, the SFSNP uses the state transition marking algorithm to reduce redundant test cases. By using the stateful rule tree of the protocol, the SFSNP extracts the constraints in the protocol specifications to construct semi-valid fuzz testing cases within the sub-protocol domain, and finally forms fuzzing sequences. Experimental results indicate that the SFSNP is reasonably effective at reducing the quantity of generated test cases and improving the quality of fuzz testing cases. The SFSNP can reduce redundancy and shorten testing time.

关键词： network protocol fuzzing extended finite state machine test sequence state transition markingalgorithm semi-valid algorithm

Test Data Generation for Stateful Network Protocol Fuzzing Using a Rule-Based State Machine

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Tsinghua Science and Technology 2016年第3期21卷 352-360页

作者： Rui Ma Daguang Wang changzhen hu Wendong Ji Jingfeng Xue Beijing Key Laboratory of Software Security Engineering Technology School of Software Beijing Institute of Technology

To improve the efficiency and coverage of stateful network protocol fuzzing, this paper proposes a new method, using a rule-based state machine and a stateful rule tree to guide the generation of fuzz testing data. The method first builds a rule-based state machine model as a formal description of the states of a network protocol. This removes safety paths, to cut down the scale of the state space. Then it uses a stateful rule tree to describe the relationship between states and messages, and then remove useless items from it. According to the message sequence obtained by the analysis of paths using the stateful rule tree and the protocol specification, an abstract data model of test case generation is defined. The fuzz testing data is produced by various generation algorithms through filling data in the fields of the data model. Using the rule-based state machine and the stateful rule tree, the quantity of test data can be reduced. Experimental results indicate that our method can discover the same vulnerabilities as traditional approaches, using less test data, while optimizing test data generation and improving test efficiency.

关键词： fuzzing stateful network protocol test data generation rule-based state machine stateful rule tree

Software Defect Prediction via Deep Belief Network

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Chinese Journal of Electronics 2019年第5期28卷 925-932页

作者： WEI hua SHAN Chun hu changzhen ZHANG Yu YU Xiao School of Computer Science and Technology Beijing Institute of Technology China Information Technology Security Evaluation Center Beijing Key Laboratory of Software Security Engineering Technology Beijing Institute of Technology School of Electrical and Information Engineering and Beijing Key Laboratory of Intelligent Processing for Building Big Data Beijing University of Civil Engineering and Architecture State Key Laboratory in China for Geomechanics and Deep Underground Engineering (Beijing) China University of Mining and Technology School of Computer Science and Technology Shandong University of Technology

Defect distribution prediction is a meaningful topic because software defects are the fundamental cause of many attacks and data loss. Building accurate prediction models can help developers find bugs and prioritize their testing efforts. Previous researches focus on exploring different machine learning algorithms based on the features that encode the characteristics of *** problem of data redundancy exists in software defect data set, which has great influence on prediction *** propose a defect distribution prediction model(Deep belief network prediction model, DBNPM), a system for detecting whether a program module contains defects. The key insight of DBNPM is Deep belief network(DBN)technology, which is an effective deep learning technique in image processing and natural language processing,whose features are similar to defects in source *** results show that DBNPM can efficiently extract and process the data characteristics of source program and the performance is better than Support vector machine(SVM), Locally linear embedding SVM(LLE-SVM), and Neighborhood preserving embedding SVM(NPE-SVM).

关键词： Defect prediction Software security Deep belief network(DBN)

Software System Evolution Analysis Method Based on Algebraic Topology

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Tsinghua Science and Technology 2018年第5期23卷 599-609页

作者： Chun Shan Liyuan Liu Jingfeng Xue changzhen hu Hongjin Zhu School of Software Beijing Institute of Technology Beijing 100081 China

The analysis of software system evolution is highly significant in software research as the evolution runs throughout the lifecycle of a software system. Considering a software system as an algebraic engineering system, we propose a software system evolution analysis method based on algebraic topology. First, from a complex network perspective, we abstract a software system into the software structural topology diagram. Then, based on the algebraic topology principle, we abstract each node in the software structural topology diagram into an algebraic component represented by a 6-tuple. We propose three kinds of operation relationships between two algebraic components, so that the software system can be abstracted into an algebraic expression of components. In addition, we propose three forms of software system evolution, which help to analyze the structure and evolution of system software and facilitate its maintenance and reconfiguration.

关键词： software structural topology diagram algebraic component topological complex evolution

A Practical Online Approach to Protecting Kernel Heap Buffers in Kernel Modules

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China Communications 2016年第11期13卷 143-152页

作者： Donghai Tian Xiaoqi Jia Junhua Chen changzhen hu Jingfeng Xue Beijing Key Laboratory of Software Security Engineering Technique School of SoftwareBeijing Institute of Technology Shanghai Key Laboratory of Integrated Administration Technologies for Information Security Shanghai Jiao Tong University State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of Sciences & University of Chinese Academy of Sciences Key Laboratory of IOT Application Technology of Universities in Yunnan Province Yunnan Minzu University

Heap overflow attack is one of the major memory corruption attacks that have become prevalent for decades. To defeat this attack,many protection methods are proposed in recent years. However,most of these existing methods focus on user-level heap overflow detection. Only a few methods are proposed for kernel heap protection. Moreover,all these kernel protection methods need modifying the existing OS kernel so that they may not be adopted in practice. To address this problem,we propose a lightweight virtualization-based solution that can protect the kernel heap buffers allocated for the target kernel modules. The key idea of our approach is to combine the static binary analysis and virtualization technology to trap a memory allocation operation of the target kernel module,and then add one secure canary word to the end of the allocated buffer. After that,a monitor process is launched to check the integrity of the canaries. The evaluations show that our system can detect kernel heap overflow attacks effectively with minimal performance cost.

关键词： kernel heap overflow virtualization technology kernel module

Software Defect Distribution Prediction Model Based on NPE-SVM

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China Communications 2018年第5期15卷 173-182页

作者： hua Wei Chun Shan changzhen hu huizhong Sun Min Lei School of Computer Science and Technology Beijing Institute of TechnologyBeijing 100081China China Information Technology Security Evaluation Center Beijing 100085China Beijing Key Laboratory of Software Security Engineering Technology School of SoftwareBeijing Institute of TechnologyBeijing 100081China Information Security Center Beijing University of Posts and TelecommunicationsBeijing 100876China Guizhou University Guizhou Provincial Key Laboratory of Public Big DataGuizhou Guiyang 550025China

During the prediction of software defect distribution, the data redundancy caused by the multi-dimensional measurement will lead to the decrease of prediction accuracy. In order to solve this problem, this paper proposed a novel software defect prediction model based on neighborhood preserving embedded support vector machine(NPESVM) algorithm. The model uses SVM as the basic classifier of software defect distribution prediction model, and the NPE algorithm is combined to keep the local geometric structure of the data unchanged in the process of dimensionality reduction. The problem of precision reduction of SVM caused by data loss after attribute reduction is avoided. Compared with single SVM and LLE-SVM prediction algorithm, the prediction model in this paper improves the F-measure in aspect of software defect distribution prediction by 3%~4%.

关键词： data redundancy SVM NPE algorithm dimensionality reduction