一种安全性更高的正形置换发生器

作为一种完全映射,正形置换是对称密码体制中一类重要的基础置换.正形置换已经被证明拥有完全平衡性.自1995年以来,国内外学者对于正形置换的研究主要集中在构造与计数方面,但是对于正形置换的密码学性质,比如差分均匀度和非线性度等则相对关注得较少,而具有良好密码学性质的正形置换可以直接用来设计对称密码算法中的密码学部件.修正了一个关于复合函数密码学性质的结论中关于非线性度所存在的问题;接着分析了一般BDLL正形置换发生器的抗差分分析和抗线性分析的密码学性质;然后基于复合函数提出了一种改进的正形置换发生器,并结合修正后的复合函数结论证明了该正形置换发生器相比于一般BDLL正形置换发生器,能够生成数量更多、拥有更高非线性度和代数次数的非线性正形置换.     

基于并置方法构造的正形置换性质研究

正形置换在密码体制中有重要应用,根据正形置换和正形拉丁方截集的等价关系,研究了基于并置方法构造的正形置换的线性性、不动点、轮换和周期,给出了一些具体的结果。     

正形置换的枚举与计数

正形置换在密码算法的设计中占有很重要的地位．研究正形置换的特性、枚举、计数对于密码设计和密码分析均具有重要的意义．正形置换的理论研究已成为国内外密码学编码理论的热点问题．对正形置换的计数和枚举问题进行讨论，利用和阵给出了正形置换的一个枚举方法，利用该方法可以列出所有的”阶正形置换．国内外相关文献中还未见到正形置换的枚举方法．由该枚举法得出了n阶正形置换个数Nn的上界和下界，这个结果比迄今为止给出的结果都要好，是目前给出的最优上下界．     

正形置换的一种新递归构造方法

提出了复合截集的概念,基于复合截集给出了由n元正形置换构造n+1元正形置换的新的递归构造方法,并解决了相应的计数问题。     

满足若干密码学性质的S-盒的构造

S-盒是许多密码算法的唯一非线性部件,它的密码强度决定了整个密码算法的安全强度.但 是对于大的S-盒的构造比较困难,而且软硬件实现也比较难,目前比较流行的是8×8的S-盒 .基于m-序列,提出一种构造8×8与8×6的S-盒的方法,通过测试法从中选出了一批非线性 性质与差分均匀性都比较好的S-盒.同时,基于正形置换构造了一批4×4的S-盒.这些S-盒 对进一步设计密码算法提供了非线性资源.     

Lai-Massey模型的差分和线性可证明安全性

1991年,Lai 和Massey 设计了IDEA算法.该算法首次用到了Lai-Massey模型.1999年,Vaudenay在Lai-Massey模型中引入正形置换或几乎非正形置换,证明了该Lai-Massey 模型满足Luby-Rackoff定理.主要对Lai-Massey模型的差分和线性可证明安全性进行研究.首先,给出了Lai-Massey模型中差分活动F 函数个数的下确界.其次,证明了当F函数是正形置换时,Lai-Massey模型的差分活动F函数个数下确界与Feistel模型中活动F函数个数的下确界一样.最后,通过引入对偶模型,证明了Lai-Massey模型的差分传递链和组合传递链在结构上的对偶性,并基于该对偶性直接给出了Lai-Massey模型的线性可证明安全性.     

等价关系矩阵的置换合同性质与标准形计算

等价关系在网络分析、图论、模式识别和数据库技术等方面都有许多应用,而任意等价关系矩阵都置换合同于块1-对角矩阵标准形,从置换运算的角度分析置换合同的几条性质,提出基于图的深度优先搜索策略的置换矩阵构造算法：根据等价矩阵关系图搜索路径的性质,将图的深度优先搜索所得顶点路径与初始顶点顺序对比构造置换映射。利用置换分解原理,将置换映射分解成相应的对换乘积,得到最终置换矩阵,完成等价关系矩阵的置换相似判定。为了验证该算法的正确性和效率,设计了一个等价关系矩阵的自动生成算法。实验结果表明,置换矩阵构造算法和等价关系矩阵的自动生成算法简洁且易于理解和实现。     

Znm上的l-广义正形置换

给出了Zⁿ_m上l-广义正形置换的概念,讨论了l-广义正形置换的函数性质。对Zⁿ_m上l-广义正形置换的一阶广义Chrestenson谱特征进行了分析,并基于谱特征给出了一种Zⁿ_m上的l-广义正形置换的构造方法。     

多构造蚁群优化求解置换流水车间调度问题

针对置换流水车间调度问题,提出了一种多构造蚁群优化求解算法。在该算法中,蚁群采用两种方式构造解,分别是基于NEH(Nawaz-Enscore-Ham,NEH)启发式算法和Rajendran启发式算法,并根据解的质量,自适应地调整两种构造方式在蚁群中所占的比例。对置换流水车间调度问题的基准问题测试表明,提出的算法是有效的。     

一种新的对称动态置换密码算法-DREA

描述了一种新的对称加密算法-DREA（Dynamic Replacement Cryptography Algorithm）：通过构造一个动态置换表序列对数据进行置换，并对数据进行分块加密处理，实现分组数据的加密运算。该密码算法具有构造简单、可以抵御常见的攻击的特点，而且容易通过软件实现。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate