缓冲区溢出攻击的分析及防范措施

首先解释缓冲区溢出的概念,从程序语言本身存在缺陷,不够健壮的角度出发,对缓冲区溢出的原理进行了详细的阐述,并总结出缓冲区溢出攻击的类型;最后,结合缓冲区溢出攻击的类型,从系统管理和软件开发两个角度提出缓冲区溢出攻击的防范措施.     

在程序编码中防止缓冲区溢出

缓冲区溢出攻击是各种网络攻击方法中较普遍且危害较严重的一种，文章分析了缓冲区攻击的原理，并从编程角度分析了造成缓冲区溢出的潜在漏洞，最后提出了在程序编写过程中防御缓冲区溢出的方法。     

Linux下缓冲区溢出的分析与利用

缓冲区溢出漏洞攻击是目前互联网上黑客使用最多的攻击手段之一。论文针对Linux平台,从Linux系统内存管理机制人手,解释了Linux系统下函数调用的方法,分析了缓冲区溢出产生的原因并阐明了缓冲区溢出产生的整个过程,通过具体实例,说明了缓冲区溢出的利用方法。     

一种防止缓冲区溢出攻击的新方法

介绍了缓冲区溢出攻击的原理，分析了缓冲区的三种结构，简要总结了已有的检测方法。提出了一种新的简单、易实施的防御缓冲区溢出攻击的方法。     

基于目标码的缓冲区溢出漏洞发现的研究

对缓冲区溢出进行了分类，分析了缓冲区溢出需要的条件，接着针对运行时缓冲区边界定位问题，结合执行路径分析，提出了一种基于目标码的缓冲区溢出漏洞发现的体系结构，最后给出遏制利用缓冲区溢出漏洞进行攻击的一些方法。     

防御缓冲区溢出攻击的有效策略

缓冲区溢出攻击严重地危害着我们的网络安全,已经给人们带来了巨大的损失。在对现有防御技术和工具进行合理分类的基础上,文章总结其中存在的优缺点,探讨更有效防御工具的开发方向。同时针对日益增长的网络安全需求,从整个系统的角度提出了防御缓冲区溢出攻击的一种有效策略。     

基于LINUX的安全网关防御缓冲区溢出攻击的方法研究

本文分析了缓冲区溢出攻击的原理,概括linux系统针对溢出攻击的常用防御手段.进一步,分析了目前各种基于裁减linux系统的安全网关的特点,提出了其抗缓冲区溢出攻击以增强系统安全性的方法.最后说明了防溢出攻击技术的近期发展.     

基于CPU硬件的缓冲区溢出攻击的防范技术

基于软件的防护功能已经难以满足现代用户的安全需要，基于硬件的安全技术成为新的重大安全课题。文章分析了缓冲区溢出的原因、危害及溢出攻击机理，阐述了CPU硬件防范缓冲区溢出攻击的NX（No eXecutebit）技术原理及其具体实现。所述技术路线有益于国产CPU的研发。     

针对Shellcode变形规避的NIDS检测技术

现今,缓冲区溢出攻击仍是网络上最普遍和有效的攻击方式之一,常见于恶意攻击者的手动攻击以及病毒蠕虫的自发攻击。随着NIDS的发展,普通的缓冲区溢出攻击能够用基于Shellcode匹配的手段进行检测。然而,Shellcode变形技术的出现使缓冲区溢出攻击拥有了躲避NIDS检测的能力。论文在NIDS传统检测技术的基础上,详细研究了Shellcode的各种变形手段,提出了针对性的检测技术,并展望了未来的发展方向。     

浅析缓冲区溢出漏洞的研究与发展

缓冲区溢出(buffer overflow)是一种非常普遍、非常危险的漏洞,在各个操作系统、应用软件中广泛的存在。目前,缓冲区溢出漏洞已经成为一个针对软件的严重安全威胁。在溢出后攻击者通常可以获取到目标主机的最高权限,从而对目标主机发起各种各样的攻击。本文主要分析了缓冲区溢出漏洞的概念、原理,从几个方面分析和研究了目前常见的集中针对缓冲区溢出漏洞的检测的方法。最后对缓冲区溢出的未来研究热点进行阐述。     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.