Universally Composable Symbolic Analysis of Group Key Exchange Protocol

Canetti and Herzog have already proposed universally composable symbolic analysis(UCSA) to analyze mutual authentication and key exchange protocols. However,they do not analyze group key exchange protocol. Therefore,this paper explores an approach to analyze group key exchange protocols,which realize automation and guarantee the soundness of cryptography. Considered that there exist many kinds of group key exchange protocols and the participants’ number of each protocol is arbitrary. So this paper takes the case of Burmester-Desmedt(BD) protocol with three participants against passive adversary(3-BD-Passive) . In a nutshell,our works lay the root for analyzing group key exchange protocols automatically without sacrificing soundness of cryptography.

Universally Composable Three Party Password-based Key Exchange Protocol

Within the framework of universal composability,an appropriate ideal functionality that captures the basic security requirements of three party password-based key exchange was defined. An efficient real-word three party password-based key exchange protocol was also proposed.This protocol securely realizes the ideal functionality with respect to static party corruption.Thus it provides security guarantees under arbitrary composition with other protocols.

Domain ontology driven composable simulation framework

The simulation composability is one of important development directions in simulation domain. The key issue is the semantic composability. Currently there is no feasible approach to realize the effective semantic representation and composition of simulation components. Based on domain knowledge and Web Ontology Language (OWL), this paper proposes a composable simulation framework, which includes conceptual model semantics, model components semantics, model framework semantics, and simulation scenario semantics. Additionally, all the semantics are utilized in the model components development process, the simulation system development process, and the simulation system execution process respectively. The consistency checking among those semantics is also proposed. The detailed mapping processes between different semantic models can help to build the domain ontology driven composable simulation system.

Universally composable anonymous Hash certification model

Ideal function is the fundamental component in the universally composable security model. However, the certification ideal function defined in the universally composable security model realizes the identity authentication by binding identity to messages and the signature, which fails to characterize the special security requirements of anonymous authentication with other kind of certificate. Therefore, inspired by the work of Marten, an anonymous hash certification ideal function and a more universal certificate CA model are proposed in this paper. We define the security requirements and security notions for this model in the framework of universal composable security and prove in the plain model （not in the random-oracle model） that these security notions can be achieved using combinations of a secure digital signature scheme, a symmetrical encryption mechanism, a family of pseudorandom functions, and a family of one-way collision-free hash functions. Considering the limitation of wireless environment and computation ability of wireless devices, this anonymous Hash certification ideal function is realized by using symmetry primitives.

Universal composable secure protocol for EPC system

As an important component of internet of things, electronic product code （EPC） system is widely used in many areas. However, the mass deployment of EPC system is frequently degraded by security and privacy problems. Therefore, the major researches focus on the design of a secure EPC system with high efficiency. This paper discusses the security requirements of EPC system and presents a universal composable （UC） model for EPC system, the ideal functionality of EPC system is also formally defined with the UC framework. Then a secure protocol for EPC system under UC framework is proposed and the analysis of security and performance of the proposed protocol is given, in comparison with other protocols, the results show that the proposed protocol is UC secure and can provide privacy protection, untraceability, authorized access, anonymity and concurrent security for EPC system. Furthermore, less computation and storage resource are required by the proposed protocol.

基于开源技术的高校OJ系统部署运维与应用

近年来,全国高校越来越重视对大学生实践能力的培养,其中的关键一环是提升学生的编程能力。传统程序设计课程存在诸如实践时间不足、师资力量薄弱、无法及时辅导学生之类的问题,OJ(OnlineJudger)系统在这种情景下应运而生。该文旨在研究和推广开源OJ平台及其相关技术,将其应用于厦门华厦学院教学和程序设计竞赛活动之中,形成一套基于在线评测系统的课程教学和学科竞赛竞训方案。实践结果表明,校园OJ系统不仅可以激发学生的学习兴趣进而提高他们的编程开发能力,还可以改善课堂教学效果以及提升教师的管理能力。

Universally composable oblivious transfer from ideal lattice

As a fundamental cryptographic primitive, oblivious transfer (OT) is developed for the sake of efficient usability and combinational feasibility. However, most OT protocols are built upon some quantum non-immune cryptosystems by assuming the hardness of discrete logarithm or factoring problem, whose security will break down directly in the quantum setting. Therefore, as a subarea of postquantum cryptography, lattice-based cryptography is viewed as a promising alternative and cornerstone to support for building post-quantum protocols since it enjoys some attractive properties, such as provable security against quantum adversaries and lower asymptotic complexity. In this paper, we first build an efficient 1-out-of-2 OT protocol upon the hardness of ring learning with errors (RLWE) problem, which is at least as hard as some worst-case ideal lattice problems. We show that this 1-out-of-2 OT protocol can be universally composable and secure against static corruptions in the random oracle model. Then we extend it to a general case, i.e., 1-out-of-N OT with achieving the same level of security. Furthermore, on the basis of the above OT structure, we obtain two improved OT protocols using two improved lattice-based key exchange protocols (respectively relying on the RLWE problem and learning with errors (LWE) problem, and both achieving better efficiency by removing the Gaussian sampling for saving cost) as building blocks. To show that our proposed OT protocol indeed achieves comparable security and efficiency, we make a comparison with another two lattice-based OT protocols in the end of the paper. With concerning on the potential threat from quantum computing and expecting on the practical use of OT with high efficiency, an efficient post-quantum OT protocol is pressing needed. As shown in this paper, our proposed OT protocols may be considered as post-quantum OT candidates since they can both preserve provable security relying on lattice problems and enjoy practical efficiency.

Universally Composable Proactive Threshold RSA Signature

Recently some efforts were made towards capturing the security requirements within the composable security framework. This modeling has some significant advantages in designing and analyzing complex systems. The threshold signature was discussed and a definition was given based on the universal composability framework, which is proved to be equivalent to the standard security definition. Furthermore, a simple, efficient and proactive threshold RSA signature protocol was presented. It is proved to be correct, consistent and unforgeable relative to the environment that at most t - 1 parties are corrupted in each proactive stage. It is also secure under the universal composability framework. It is a UC based security and is proved to be equivalent to the standard security.

Building a hybrid DEVS and GRASS model using a composable cellular automaton

Modeling and simulation is pervasive throughout many different disciplines.As computing technology has provided more capability,the systems being modeled and simulated have grown larger and more complex.Often times,these large systems are managed as interacting subsystems.When it is necessary for the simulation to allow disparate subsystems to maintain their independence,then a hybrid model of the subsystems should be used.Furthermore,to ease the burden of verification and validation of simulation results,a proven system theoretical modeling specification should be used.However,many communities have already adopted nonsystem theoretical software solutions and established a group of domain experts familiar with these tools.This paper provides two things:a formal approach to building a hybrid model,and a discussion of how to incorporate a nonsystem theoretical software implementation into a proven framework.The first is done through the implementation of a Knowledge Interchange Broker(KIB)as an Interaction Model(IM).The second is accomplished by exemplifying the use of the IM in an agent-environment hybrid model.In the hybrid model,the agent is implemented in the Discrete-event System(DEVS)specification and the environment is implemented in the Geographical Resources Analysis Support System(GRASS)using a Composable Cellular Automaton(CCA)specification.This concept has been successfully applied to both example models and an interdisciplinary research project where the interactions between human activities and landscape processes are studied.

融合数字多模态写作的英语专业课程思政生态给养研究——基于“讲好中国故事”视角

在英语专业学生基于数字多模态写作DMC“讲好中国故事”的实践基础上,借鉴生态给养理论和多模态理论等,构建英语专业课程思政生态给养的框架模式,以此探索高校外语课程思政的新思路。本研究基于质性研究和调查问卷,纵向探讨了师生在DMC实践的各个流程中为课堂思政整体分别提供怎样的生态给养,横向分析了生态给养的各级维度的具体内容。研究发现:师生共同参与下的“讲好中国故事”英语生态化课程思政课堂实践能够取得积极效果。

一种水体中有机污染物快速筛查与半定量的方法及其应用

采用液液萃取法富集水体中的有机污染物,以气相色谱-质谱和Compound composer软件进行筛查和半定量计算,同时以气相色谱-质谱法在选择离子模式下对Compound composer软件的半定量结果进行验证,结果表明除3-氨基苯酚、豆甾醇和β-谷甾醇外,其它物质的回收率在74%～102%之间,保留时间偏差为-0.158～0.049 min,对添加量为1.0μg目标物的水样半定量,结果偏差在-0.48～0.62μg之间。在无标准样品的条件下,利用Compound composer软件及其自带含近千种化合物标准曲线的数据库,对江苏省南通、苏州和无锡三市的地表水环境样品进行监测,筛查其中主要的有机污染物,并进行半定量计算。三市地表水样中共检出47种有机污染物。2,6-二叔丁基-4-甲基苯酚为检出浓度最高的化合物,其浓度达140μg·L-1,酞酸酯类和多环芳烃类物质普遍存在,其单体浓度范围分别为1.7～48μg·L-1和0.13～9.6μg·L-1。依照GB3838-2002《地表水环境质量标准》,三市地表水体中酞酸酯类严重超标,水体中总有机物污染状况应引起关注。

虚拟DCS工程翻译的设计与实现

介绍了以ABB Composer 4.2工程项目为研究对象,使用二进制文件分析技术和Microsoft Visio的二次开发技术设计的ABB Composer 4.2虚拟DCS工程翻译系统。实际工程测试表明,该工程翻译系统能够对ABB Composer 4.2组态环境进行全范围的转换翻译。

用于网络教学的虚拟仿真交互式课件研究

网络教学急需交互式课件。利用CATIA建立机械产品的虚拟模型,实现机器拆装和工作过程的虚拟仿真。将虚拟仿真制作动画视频后嵌于具有交互性的Flash软件中,生成可在网络上使用的虚拟仿真网络课件。也可以将CATIA虚拟模型直接导入到3DVIA Composer软件中,制作虚拟仿真课件。两种方法制作的课件方便学生在网络上自主学习。

Failure characteristics of three-body model composed of rock and coal with different strength and stiffness

Four different types of three-body model composed of rock and coal with different strength and stiffness were established in order to study the failure characteristics of compound model such as roof-coal-floor. Through stress analysis of the element with variable strength and stiffness extracted from the strong-weak interface, the tri-axial compressive strength of the weak body and strong body near the interface as well as the areas away from the contact surface was found. Then, on the basis of three-dimensional fast Lagrangian method of continua and strain softening constitutive model composed of Coulomb-Mohr shear failure with tensile cut-off, stress and strain relationship of the four three-body combined models were analyzed under different confining pressures by numerical simulation. Finally, the different features of local shear zones and plastic failure areas of the four different models and their development trend with increasing confining pressure were discussed. The results show that additional stresses are derived due to the lateral deformation constraints near the strong-weak interface area, which results in the strength increasing in weak body and strength decreasing in strong body. The weakly consolidated soft rock and coal cementation exhibit significant strain softening behavior and bear compound tension-shear failure under uni-axial compression. With the increase of confining pressure, the tensile failure disappears from the model, and the failure type of composed model changes to local shear failure with different number of shearing bands and plastic failure zones. This work shows important guiding significance for the mechanism study of seismic, rock burst, and coal bump.

方向关系矩阵的复合

采用方向关系矩阵模型表示空间区域最小边界矩形(MBR)间的关系,形式化描述了Skiadopoulos等提出的方向关系复合思想,并对其进行细化,提出方向关系矩阵复合方法,使方向关系复合易于实现;简化了Most运算,使复合过程更加简洁;通过定义取极小和取极大算子,实现了Most算法,为复合算法的提出奠定了基础;定义求幂运算符,实现了复合算法Com-pose并证明了算法的正确性,Compose算法的实现使方向关系复合从理论向应用更进一步。

基于DM642图像处理的镁熔液第一气泡检测

传统的镁熔液第一气泡检测结果存在较大滞后性,且以Matlab为代表的检测工具又受限于工程应用,本文提出一种基于DSP检测弱小目标的新思路,构建了一个以DM642为主处理器的嵌入式图像处理系统平台,并利用C语言在DSP集成开发软件Code Composer Studio 3.3上进行算法编程,实现了镁熔液第一气泡的检测。实验结果验证了镁熔液第一气泡检测方法在实际应用中的可行性。

GCMS结合Compound Composer软件筛选PM2.5中有机污染物

本文采用高压溶剂萃取(HPSE)方式萃取PM_2.5滤膜中的有机污染物,以气相色谱-质谱(GCMS)和Compound Composer软件进行筛查和半定量计算,同时以已知浓度的农药标样对Compound Composer软件的定性及半定量结果进行验证.结果表明,对1.0μg·L^(-1)的24种农药混标进行半定量分析,结果偏差在-0.707—0.643μg之间,相对误差在-70.74%—64.31%之间满足日常环境监测的要求.在无标样的情况下,对某地区不同时间的3个PM_2.5样品进行监测,筛查其中主要的有机污染物,并进行半定量计算,可及时掌握大气污染现状,为环境管理和来源解析提供有效数据.

基于Symphony DCS Composer组态语言与C语言联合编程的在线性能计算

提出了1种采用美国ABB公司的Symphony DCS Composer组态语言与C语言联合编程的方法,采用C语言编制在线性能计算程序,Composer组态语言调用C语言程序,将DCS实时数据作为计算数据,计算得到单元机组能耗特性。C语言程序包含了基于IAPWS-IF97公式的焓熵值计算程序,集成一体化计算环境,无需调用其它程序,解决了DCS组态语言存在的对于复杂算法的局限性,实现了机组的在线性能计算。以某电厂1台660 MW机组为研究对象,对机组660 MW负荷下的煤耗进行了计算,计算结果误差在允许范围内,表明该在线计算方法可行。

基于DSP的自适应弱小目标检测方法

针对复杂背景下弱小目标检测的难题,提出一种基于DSP的自适应背景预测弱小目标检测新方法。该方法在DSP为核心的嵌入式图像处理系统平台上,以自适应背景预测算法为基础,在DSP集成开发软件Code Composer Studio 3.3上采用C语言编写弱小目标检测程序。根据图像的相邻像素的灰度特性选取不同的背景预测模型对连续四帧原始图像进行自适应背景预测得到背景预测图像,背景预测图像与原始图像相减得到残差图像;对残差图像采用交叉差分算法和自适应阈值分割处理得到二值图像;对二值图像采用逻辑与运算和形态学开运算,获得真实弱小目标。实验结果表明,该方法可以有效地检测到弱小目标,且与中值滤波算法相比,该算法预处理时间减少22%,虚警概率降低6%,检测到的目标面积增大2.3倍,更有利于目标点的观察,为工业现场镁合金熔液中弱小目标实时检测奠定了基础。

基于MATLAB/Simulink平台下TI C2000 DSP代码的自动生成

针对传统的DSP代码开发周期较长、效率低等缺点,详细介绍了一种快速、高效的DSP代码开发流程。利用MAT-LAB、S imu link、Real-Tim e W orkshop、DSP B locksets工具箱和TI公司的开发工具CCS IDE,在S imu link环境下,用图形化的方式设计DSP程序,实现代码的自动生成。完成了DSP系统设计到实施的无缝集成,缩短了开发周期。利用该方法所设计的直流力矩电机控制系统已在TMS320F2812开发板上顺利运行。