一种新的移动Agent保护方案研究与设计

随着移动Agent技术在分布式计算中的应用，移动Agent系统在安全和软件工程两方面面临着巨大的挑战。为了防止恶意或未授权的第三方实体的攻击，研究了保护移动Agent数据和代码的方法。设计了一种全新的移动Agent结构，由封装了所有要在特定主机平台上执行的代码的数据和负责传送并处理这些数据的显示代码构成，这种数据代码分离结构与其他已有的移动Agent结构互不影响，因而提高了移动Agent平台之间的互操作性。同时描述了公钥解密和Agent验证机制，实现了保护数据免受篡改代码引起的攻击，以及通过进一步改进数据的结构，实现了保护代码免受注入恶意数据引起的攻击。     

基于MASS和JavaCard的移动代理安全模型

探讨了移动代理防范恶意主机的攻击问题，提出了一个基于移动代理安全服务器和JavaCard的安全模型。模型中的通信信息进行了签名和加密，可以防止恶意主机窥视和篡改代理的代码和数据，也能防止恶意主机伪造移动代理。安全机制中能进行异常情况处理，较好地了解决恶意对移动代理的攻击问题。模型中JC证书的管理和更新问题需进一步研究。     

基于行为特征的恶意代码检测方法

本文分析总结了恶意代码的行为特征,提出了一种分析API序列来检测恶意代码的方法.该方法在传统攻击树模型中添加了时间、参数调用等语义相关信息,提升了攻击树模型对代码行为的描述能力,并对恶意代码中常见的危险API调用序列进行建模.通过虚拟执行的方法获取代码的API调用序列.并将这些序列与扩展模型进行模式匹配.发现代码中的恶意行为,计算其威胁指数,进而检测代码是否具有恶意性.     

基于shellcode检测的缓冲区溢出攻击防御技术研究

缓冲区溢出攻击对计算机和网络安全构成极大威胁。从缓冲区溢出攻击原理和shellcode实现方式出发，提出针对shellcode的溢出攻击防御技术。描述shellcode获取控制权前后，从代码特点、跳转方式及shellcode恶意功能实现过程等方面入手，检测并阻止shellcode以对抗溢出攻击的几种技术。最后对这些技术的优缺点进行比较分析，指出其中较为优秀的方法，并就更全面提高系统安全性提出了一些建议。     

基于硬件资源访问控制的固件恶意行为研究*

固件与传统的应用软件一样,都有可能存在木马、后门、逻辑炸弹等具有恶意行为的代码。由于固件具有硬件相关性、任务执行的阶段性与高内聚性等特点,使得传统的程序恶意行为描述方法不能适用于固件程序。探讨了固件程序及固件恶意行为的特点和本质特征,描述了一种基于硬件资源访问控制策略的固件程序恶意行为形式化建模和检测方法,并对该方法的有效性进行了实验验证。     

目标代码混淆技术综述

逆向工程领域的进步，一方面提升了软件分析能力，另一方面，给软件安全带来更大的挑战。目标代码混淆技术是对软件进行保护的一种有力手段，能够有效地阻挡对软件的恶意分析。文中从逆向分析的角度出发介绍了目标代码混淆技术的分类及几种典型的目标代码混淆技术的实现及混淆效果。     

恶意DNS流量攻击研究

DNS是重要的基础设施,用于域名服务,在负载均衡、移动IP等方面也有着重要的应用.分析了针对DNS的几种攻击行为类别,讨论了DNS流量激增对互联网的正常运作的影响,并提出了恶意DNS流量攻击、蜂窝效应概念,给出了几种导致DNS流量激增的措施,给出了能导致互联网DNS流量激增VC#的实例代码,最后讨论了针对DNS流量攻击的应对措施.     

融合加密与水印的移动终端代码防篡改研究

针对不法分子通过篡改移动终端设备代码获取利益的问题,提出了一种融合加密与水印的移动终端代码防篡改方法.对移动终端代码遭受篡改的原因、代码篡改攻击技术,以及风险评估方面分别进行分析,作为加密与水印算法的设计依据.修改AES算法中的轮边界,对其进行拆分和补充,将密钥信息藏于查找表中,并对乱码进行混淆处理,从而增强密钥信息的保护效果.通过代码的加密和自解密机制,将代码转换成不可阅读的密钥代码,采用自检技术检验代码是否被篡改,将加密算法与混沌序列相结合,利用不敏感段的代码哈希值,对敏感代码段进行保护,防止攻击者对移动终端代码的恶意篡改.实验结果表明,采用融合加密与水印算法处理后的程序与原始程序相似度很高,隐蔽性很好,攻击者很难对程序代码进行有效的篡改攻击.     

软件代码的恶意行为学习与分类

传统的静态特征码检测方法无法识别迷惑型恶意代码,而动态检测方法则需要消 耗大量资源;当前,大多数基于机器学习的方法并不能有效区分木马、蠕虫等恶意软件的子类别。为此,提出一种基于代码恶意行为特征的分类方法。新方法在提取代码恶意导向指令特征的基础上,学习每种代码类别特有的恶意行为序列模式,进而将代码样本投影到由恶意行为序列模式构成的新空间中。同时基于新特征表示法构造了一种近邻分类器对恶意代码进行 分类。实验结果表明,新方法可以有效地捕捉代码的恶意行为并区分不同类别代码之间的行为差异,从而大幅提高了恶意代码的分类精度。     

静动态结合的恶意Android应用自动检测技术

随着移动互联网的快速发展,移动终端及移动应用在人们日常生活中越来越重要,与此同时,恶意移动应用给网络和信息安全带来了严峻的挑战。Android平台由于其开放性和应用市场审查机制不够完善,使其成为了移动互联网时代恶意应用的主要传播平台。现有的恶意应用检测方法主要有静态分析和动态测试两种。一般而言,静态分析方法代码覆盖率高、时间开销小,但存在误报率较高的问题;而动态测试准确度较高,但需要实际运行应用,所需的时间和计算资源开销较大。针对上述情况,本文基于静动态结合的方法,自动检测恶意Android应用。首先,使用静态分析技术获取应用API的调用情况来判定其是否为疑似恶意应用,特别是可有效检测试图通过反射机制调用API躲避静态分析的恶意应用;然后,根据疑似恶意应用UI控件的可疑度进行有针对性的动态测试,来自动确认疑似恶意应用中是否存在恶意行为。基于此方法,我们实现了原型检测工具框架,并针对吸费短信类恶意行为,对由465个恶意应用和1085个正常应用组成的数据集进行了对比实验。实验结果表明,该方法在提高恶意应用检测效率的同时,有效地降低了误报率。     

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