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。     

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。     

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。     

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。     

C库中易受缓冲区溢出攻击的脆弱函数分析

为了编写更安全的C程序和提高已有C程序的安全性,对C库函数中易受缓冲区溢出攻击的脆弱函数进行了分析,分析它们可能产生缓冲区溢出时的特征及如何避免缓冲区溢出.实现了一种缓冲区溢出检测工具,能较准确地检测到C目的程序中的缓冲区溢出漏洞,分析结果具有实用价值.     

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.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

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.     

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.     

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.     

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.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.