网络蠕虫预警与隔离控制方法研究

随着互联网的迅速发展,蠕虫对于网络安全的威胁日益严重。本文介绍了蠕虫的相关概念、传播方法、特点及其危害,分析了当前针对网络蠕虫的主要预警检测方法,探讨了网络蠕虫的隔离控制方法。     

网络蠕虫的扫描方法分析

对网络上计算机系统的扫描是网络蠕虫传播的第一步,网络蠕虫扫描算法是研究蠕虫传播特性的一个基础环节。通过对常见的网络蠕虫扫描算法的研究,将其进行了分类,并对每一种扫描方法的基本原理及特点进行了分析。     

基于失败连接分析和P2P的未知网络蠕虫检测

针对现有的网络蠕虫检测系统大多不能有效快速检测慢速蠕虫的问题,本文提出使用本地失败连接分析(LF-CA)算法在蠕虫传播早期高效实时的检测本地局域网内的蠕虫,并在全局上建立可扩展性强非集中式的基于Chord算法的全网协作P2P检测机制,以信息共享的方式对慢速传播蠕虫进行检测。通过实验仿真验证了LFCA算法对本地网络的快速蠕虫有高效的检测效果和较低的误报率,证明了基于P2P技术进行信息共享协同检测比单点检测能更快更有效地检测到慢速蠕虫。     

基于混合对抗技术的对抗性蠕虫

作为对抗网络蠕虫的一种技术手段,对抗性蠕虫正在引起恶意代码研究领域的关注。然而当前对抗性蠕虫所采用的主动对抗技术和被动对抗技术存在若干缺陷,无法全面有效抑制网络蠕虫的传播。为此提出一种改进的基于混合对抗技术的对抗性蠕虫,通过构建蠕虫对抗模型以及仿真实验对其进行分析,并表明其能够在有效抑制网络蠕虫传播的同时降低对网络资源的恶意消耗。     

基于随机进程代数的P2P网络蠕虫对抗传播特性分析

 研究P2P网络中良性蠕虫和恶意蠕虫在对抗传播过程中的特性,可为制定合理的蠕虫对抗策略提供科学依据.提出一种基于随机进程代数的P2P网络蠕虫对抗传播的建模与分析方法.首先,分析了传播过程中蠕虫之间的对抗交互行为以及网络节点的状态转换过程;然后,利用PEPA语法建立了恶意蠕虫初始传播阶段与蠕虫对抗阶段的随机进程代数模型;最后,采用随机进程代数的流近似方法,推导得到能够描述蠕虫传播特性的微分方程组,通过求解该方程组,分析得到P2P蠕虫的对抗传播特性.试验结果表明,良性蠕虫可以有效遏制P2P网络中的恶意蠕虫传播,但需要根据当前的网络条件制定科学的传播策略,以减少良性蠕虫自身的传播对网络性能的影响.     

分布式蠕虫流量检测技术

分析了网络蠕虫病毒的传播特点和已有的检测方法,针对慢速传播蠕虫病毒,提出了基于流量异常传播序列的检测算法,并通过分布式系统结构,综合多个子网的检测结果,进一步提高检测准确率。模拟实验证明：该算法可以根据流量特征,在蠕虫病毒慢速传播的早期检测到该病毒的传播行为,并获得传播所用网络协议和目标端口。     

基于SSFNet的网络蠕虫实验床

网络蠕虫实验床是研究网络蠕虫传播及网络安全的一个重要平台，它克服了传统实验方法中安全性低，成本高的不足，提出一个新的蠕虫仿真实验手段。介绍了SSFNet网络仿真软件，说明其在网络研究过程中的使用价值：重点介绍了利用SSFNet网络仿真软件的Worm蠕虫包来设计和实现网络蠕虫实验床的方法，并在该实验床上模拟一种类Flash蠕虫，所得实验结果在可靠的数值范围内，说明该实验床是可行，有效的。     

蠕虫建模仿真及检测技术研究进展

计算机网络蠕虫作为当前互联网所面临的最为严重的安全威胁之一,对其进行细致的研究显得尤为重要。为了体现网络蠕虫技术研究方面的最新成果,针对当前网络蠕虫技术研究领域的热门方向,整理并分析了蠕虫传播模型和蠕虫软件仿真技术等方面的研究思路和成果,并对多种新型的网络蠕虫检测技术进行了分析和评估。最后根据研究结果,对网络蠕虫技术研究的新方向进行了总结与展望。     

一种基于网状关联分析的网络蠕虫预警新方法

通过对网络蠕虫行为模式的分析,提出一种基于网状关联分析的网络蠕虫预警的新方法,并设计了预警算法,建立了网络蠕虫预警模型和基于预警算法的原型系统,最后给出相关实验数据和分析结果。与现有的网络蠕虫检测方法相比校,新方法更加有效,而且能够预警未知的网络蠕虫。     

基于网络流量自相似性的蠕虫攻击检测方法研究

网络蠕虫攻击是一种危害巨大且难以防御的网络攻击方式。传统的基于特征匹配的蠕虫检测方法受限于对蠕虫特征值的提取,无法检测未知类型蠕虫的攻击。在此将表征网络流量自相性的Hurst参数应用到蠕虫攻击检测,通过对Hurst参数的变化来检测未知类型蠕虫的攻击。实验表明该方法能有效检测到网络中采用主动扫描方式传播的未知类型蠕虫攻击行为。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first