基于身份的认证密钥协商协议

密钥协商协议应该在满足安全性的条件下,使实现协议所需的计算开销尽可能小。文中提出了一个基于身份的认证密钥协商协议BAKAP(ID-Based Authenticated Key Agreement Protocol)。该协议提供了已知密钥安全性、完善前向保密性、密钥泄露安全性、未知密钥共享安全性和密钥控制安全性。在该协议中,参与者只需执行两次椭圆曲线点乘法和一次双线性运算。该协议与已有协议相比,计算代价小。     

四强度诱骗态相位匹配量子密钥分发协议

量子密钥分发(QKD)具有信息论上的无条件安全性，而相位匹配量子密钥分发(PM-QKD)是双场量子密钥分发协议(TF-QKD)的一个变体，其最近被提出用来克服没有量子中继器的点对点协议中存在的速率-距离限制。鉴于实践中不存在无限强度的诱骗态，提出了一种具有实用价值的四强度诱骗态相位匹配量子密钥分发协议，即四强度诱骗态相位匹配量子密钥分发协议。给出了该协议的安全密钥速率公式，并通过数值仿真分析了该协议的性能，证明了该协议的有效性。     

移动通信网中的安全密钥分配协议

本文将Rabin的公钥加密方案和Diffie-Hellmall的密钥交换方案相结合,提出了适用于数字移动通信网的一种安全密钥分配协议。该协议有以下特点:(1)在进行密钥交换时,增加了网络对通信双方的认证;(2)用户没有向网络中心泄漏任何秘密信息;(3)由于在协议中采用了Diffie—Hellman密钥交换系统,使得用户在安全性方面和计算复杂性方面取得了折中。最后,本文对该协议的安全性进行了分析。     

基于身份的认证密钥协商协议的安全分析与改进

对基于身份的标准模型下可证明安全的认证密钥协商协议进行安全性分析,发现恶意的密钥生成中心(PKG,pfivate key generator)能计算出所有的会话密钥,即它在无会话密钥托管模式下不满足PKG前向安全性.因此,为满足无托管的要求,提出一个改进的基于身份的认证密钥协商协议,并在标准模型下证明其为安全的认证密钥协商协议.结果表明,改进后协议满足完善前向安全性和PKG前向安全性.     

用于多媒体加密的基于身份的密钥协商协议的安全性

最近Yi等(2002)提出了一个用于多媒体加密的基于身份的密钥协商协议。协议建立在Diffie-Hellman 密钥交换协议和RSA公钥密码体系之上。Yi等分析了协议的安全性,并认为该协议对于恶意攻击是鲁棒的。然而,本文证明该协议对于某些攻击如伪造秘密信息和篡改交换消息是脆弱的,并分析了该协议受到这些攻击的原因。本文指出由于该协议内在的缺陷,该协议可能难于改善。     

基于串空间模型的WAI密钥协商协议分析

WAPI实施方案中采用WAI(WLAN Authentication Infrastructure)协议来进行密钥协商,运用串空间模型分析验证了WAI协议中的单播密钥协商协议的实施方案,指出该实施方案较之原方案,安全性有了较大的提高.同时,利用该协议STA以及AP能够实现双向身份认证,并能安全地协商到会话密钥.     

SSL协议(3.0)自动密钥管理的实现方案

分析了安全套接字层(SSL)协议(3.0)密钥管理的安全性,提出了一种实现SSL协议的密钥管理方案——自动化密钥管理方案,指出了此安全协议目前存在的问题。     

基于PCL的3GPP-AKA协议的形式化分析与证明

3GPP-AKA协议在第三代移动通信的安全性方面起着至关重要的作用,它保证了移动用户MS与VLR/HLR之间的双向认证及密钥协商.文中通过协议组合逻辑(PCL)对3GPP-AKA协议进行了形式化分析及安全性证明.分析表明3GPP-AKA协议可以满足它的安全目标,因此该协议可以安全的作为第三代移动通信中的认证和密钥分配协议.     

对Bellare-Rogaway 3PKD模型安全性定义的修正

指出Bellare和Rogaway在1995年提出的三方密钥分发模型——Bellare-Rogaway 3PKD模型的安全性定义存在缺陷。为此,设计了一个新的三方密钥分发协议P-Flaw。该协议在Bellare-Rogaway 3PKD模型下是可证明安全的。但是通过分析发现该协议不能够抵抗服务器欺骗攻击、已知会话密钥攻击和重放攻击等攻击形式,其原因在于Bellare-Rogaway 3PKD模型不能够对分发的会话密钥进行源识别。利用匹配会话的概念,修正了Bellare-Rogaway 3PKD模型的安全性定义。     

基于口令认证的密钥交换协议的安全性分析

在串空间理论模型引入了描述DH问题的方法以及分析猜测攻击的攻击者能力,对基于口令认证的密钥交换协议的安全性进行了形式化分析。提出一个对DH-EKE协议的简化,并证明了该协议的安全性:口令的秘密性,认证性,以及会话密钥的秘密性.根据分析给出基于口令认证的密钥交换协议抵抗猜测攻击的基本条件.将分析方法应用到基于口令的三方密钥交换协议上,给出单纯基于口令进行密钥交换协议的安全性需要满足的一个必要条件.     

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.     

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.     

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.     

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.     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.