一种针对Grain-v1的新差分错误攻击

通过分析流密码算法Grain-vl,提出了一种针对密钥流生成器的差分错误攻击。该攻击利用了前17轮密钥流次数较低的弱点,向LFSR的指定位置引入错误,通过差分得到17个线性无关的线性方程和80个内部状态,只需要猜测62bits的初始内部状态变量就可得到密钥种子。整个过程的计算复杂度为O(2 74,26)。结果表明,Grain-vl抗差分错误攻击的计算复杂度低于设计者宣称的O(2 80),也就是说,算法存在安全漏洞。     

基因组Translocation排序问题的改进多项式算法

该文给出基因组Transhocation排序问题的一个改进多项式算法，原算法所有存储空间O（n)，时间复杂度为O(n^3)，文中改进算法仍采用O(n)存储空间，时间复杂度为O(n^2logn),具体地，将计算Translocation距离的时间复杂度由O(n^3)改进为O(n^2),将计算Translocation序列的时间复杂度由O(n^3)改进为O(n^2logn).     

针对流密码MAG算法的已知明文攻击

基于已知明文的假设下,针对MAG算法初始化、密钥流生成阶段的不同特点,给出2个前向逆推攻击算法。对于密钥规模为 80 bit、128 bit的MAG算法,利用上述2个攻击算法只需已知前128个密钥流输出值,即可恢复其40 bit、32 bit的密钥,计算复杂度为O(214)。模拟结果表明,该方法的平均攻击时间约为9 min,攻击成功率为1。     

多轮EM结构的量子差分碰撞密钥恢复攻击

量子算法的发展和应用对密码算法的设计和分析产生了深远的影响,其中Grover量子算法和Simon量子算法在密码安全性评估中应用较多,但作为生日碰撞攻击量子化的BHT(Brassard,Hφyer,Tapp)量子算法,还没有得到具体应用,研究BHT量子算法对密码算法的分析具有重要意义.通过对多轮EM(Even,Mansour)结构进行分析,研究了经典条件和量子条件下的碰撞搜索算法与差分密钥恢复攻击的结合,对多轮EM结构进行了差分碰撞密钥恢复攻击,并从BHT量子算法的角度进行量子化.结果 表明,经典条件下,当差分传递概率2-p≥2-n/2时,r轮EM结构的差分密钥恢复攻击时间复杂度从O(2p+n)降到O(2p+n/2),速度快了2n/2倍.量子条件下,当差分传递概率2-p＞2-n/3时,结合BHT量子算法的差分碰撞密钥恢复攻击时间复杂度要优于基于Grover量子算法的差分密钥恢复攻击,显示了BHT量子算法在具体密码分析中的有效性.     

流密码Grain-128密钥恢复攻击及改进

流密码Grain-128是Grain v1算法的密钥增长版本。为探讨流密码Grain-128的安全性,指出Grain-128密钥流生成器的3个布尔函数的设计缺陷,在此基础上给出流密码Grain-128一种基于密钥流生成器中间内部状态的密钥恢复攻击。该攻击的计算复杂度和空间复杂度都为O(256)。为了抵抗该攻击,对Grain-128密钥流生成器的设计进行了改进。安全性分析表明,改进后的流密码Grain-128能够抵抗所提出的密钥恢复攻击。     

基于周期性质的新型密钥恢复攻击方法

针对Feistel, Misty与Type-1/2型广义Feistel等结构, 创新性地将Simon算法的周期性质与生日攻击思想相结合, 提出一种新型传统密钥恢复攻击. 与Simon算法可以在多项式时间内恢复周期值不同, 在传统计算环境下至少需要生日攻击界才能恢复出对应的周期值. 利用所提方法, 可以在${\rm{O}}({2^{n/4}})$的选择明文和密文条件下, 以${\rm{O}}({2^{3n/4}})$的时间复杂度恢复出5轮Feistel-F结构的密钥, 对应的存储复杂度为${\rm{O}}({2^{n/4}})$. 上述结果比Isobe和Shibutani的工作结果多扩展1轮, 并且所需的存储复杂度也更少. 对于Feistel-FK结构, 构造7轮密钥恢复攻击. 此外, 还将上述方法应用于构造Misty结构和Type-1/2型广义Feistel结构的密钥恢复攻击. 对于不同的Misty密码方案, 分别给出5轮Misty L-F和Misty R-F结构的密钥恢复攻击, 以及6轮Misty L-KF/FK和Misty R-KF/FK结构的密钥恢复攻击. 对于$d$分支Type-1型广义Feistel结构, 给出${d^2}$轮的密钥恢复攻击. 当d≥6时, 对于d分支Type-2型广义Feistel结构的新型密钥恢复攻击轮数会优于现有密钥恢复攻击轮数.     

用不可能差分法分析12轮ESF算法

轻量级分组密码算法ESF是一种具有广义Feistel结构的32轮迭代型分组密码,轮函数具有SPN结构,分组长度为64比特,密钥长度为80比特。为了研究ESF算法抵抗不可能差分攻击的能力,基于一条8轮不可能差分路径,根据轮密钥之间的关系,通过向前增加2轮、向后增加2轮的方式,对12轮ESF算法进行了攻击。计算结果表明,攻击12轮ESF算法所需的数据复杂度为O(2⁵³),时间复杂度为O(260.43),由此说明12轮的ESF算法对不可能差分密码分析是不免疫的。     

轻量级分组密码MIBS-80算法的Biclique分析

提出了针对轻量级分组密码算法 MIBS-80 的 Biclique 分析.利用两条独立的相关密钥差分路径,构造了4轮维度为4 的 Biclique 结构,在此基础上对密钥空间进行了划分,结合预计算技术,对每一个密钥子空间进行筛选以降低中间相遇攻击所需的计算复杂度,实施了对12 轮 MIBS-80 的密钥恢复攻击.攻击的数据复杂度为2⁵²个选择明文,计算复杂度约为2^77.13次12 轮 MIBS-80 加密,存储复杂度约为2^8.17,成功实施攻击的概率为1.与已有攻击方法相比,在存储复杂度及成功率方面具有优势.     

CLEFIA-128算法的不可能差分密码分析

为研究分组密码CLEFIA-128抵抗不可能差分攻击的能力,基于一条9轮不可能差分路径,分析了13轮不带白化密钥的CLEFIA-128算法。利用轮函数中S盒差分分布表恢复部分密钥,利用轮密钥之间的关系减少密钥猜测量,并使用部分密钥分别猜测(Early Abort)技术有效地降低了复杂度。计算结果表明,该方法的数据复杂度和时间复杂度分别为O(2103.2)和O(2124.1)。     

简化SIMON类算法的立方测试与分析*

针对轻量级分组密码算法SIMON的安全性分析,对SIMON32/64算法抵抗立方攻击的能力和算法内部结构对密钥比特的混淆和扩散性能力进行了评估。基于SIMON类算法的密钥编排特点和轮函数结构,结合立方分析的基本思想,利用FPGA测试平台设计了一个SIMON32/64的立方攻击和密钥中比特检测算法。测试结果表明：在立方变元取6维至24维时,对于7轮SIMON32/64算法,通过立方攻击能够直接恢复47比特密钥,攻击时间复杂度约为218.08;对于8轮SIMON32/64算法,能够直接恢复39比特密钥,攻击时间复杂度约为225.00。对于10轮,11轮SIMON32/64算法,通过立方测试均能够捕获到密钥中比特。     

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