CA认证在组织机构代码管理中的应用

针对组织机构代码管理中的若干安全问题,分析了CA认证的重要性,提出了基于CA安全技术的解决方案:采用数字加密技术保证数据的传输安全;采用数字签名技术进行身份认证;应用CA证书进行用户系统登陆的身份识别。通过建模和存储用户身份的数字证书及私钥文件的UsbKey,实现操作方便、响应迅速的代码网上业务。     

PKI技术在电子政务中的应用

电子政务的网络应用系统必然涉及到国家和本单位的秘密,涉及到多种敏感数据和各类重要文件,因此对安全保障系统有非常高的要求。例如,需要采用高安全度的身份认证手段,对网络上来访的用户进行认证;需要采取加密通信技术来保障通信数据不被窃取;需要解决网络化办公时的文件批阅和签发问题;需要采用专门的技术来保护个人计算机及其所存放文件的安全等等。近年发展起来的PKI公共密钥安全体系结合了多种密码技术,提供了数字证书、密钥安全交换和数字签名等方法,为身份认证、安全通信、保证数据的完整性和抗否认性等,提供了高安全水平的解决方…     

保密电子邮件传递过程中的法律关系研究

保密电子邮件通信是指基于SPKM机制(简单公钥机制),采用Client/Server结构,通过安全邮件服务器和安全邮件客户端软件实现电子邮件通信的信息传输模式。其运作原理是:利用公开密钥机制PKI和数字证书来实现通信双方的单向或双向身份认证;通过协商HASH算法、对称算法、对称密钥来保证传输数据的机密性和完整性;利用数字签名来保证数据的有效性和防抵赖性;运用序列号或时间戳等措施增强协议的抗攻击性。假设发送     

对企业信息的安全加密

PKI(公共密钥体系)使用一对密钥包括公开密钥(PublicKey)和私有密钥(Public Key),能够使世界上任何地方的两个人通过因特网进行信息的安全加密和身份认证。同时,在信息的交换过程中,PKI技术能够确保信息的内容不被第三方读取和篡改,以及验证通信双方身份的真实性。公开密钥由认证中心保存并发布,私有密钥由使用者秘密保存并要防止泄漏。发送方可以使用接收方的公开密钥对信息进行加密,以保证只有接收方才能打开文件。另外,文件还可以用发送方的私有密钥加密起到数字签名的作用,用以确定接收方的身份和防止日后的否认。随着越来越多的商家意识到了PKI的这一忧势,安全存储这一私钥越发显得必要。传统存储私钥的手段存在漏洞,但智能卡可提供更方便与安全的方式实现这一存储目的。     

基于Java的电子公文加密传输

如何保证政府电子政务的安全性是实施电子政务必须首先要解决的问题。介绍了信息安全领域中的公开密钥加密体系和数字签名以及Java的安全机制;针对目前办公自动化系统中电子公文传输普遍存在的安全问题,利用Java中的安全软件包实现了对电子公文的数字签名,从而保证了在政府部门内部数据传输的可认证性、完整性和不可抵赖性。     

数字认证技术及其在电子政务系统中的应用

介绍了计算机网络安全中的数字认证技术，并阐述了数字认证技术的原理和功能，以及其在电子政务系统中的一些具体应用。作为解决网络信息安全问题的开放性新技术，通过运用网络加密、电子签名以及公开密钥等电子技术手段，对网上交易主体的电子身份进行审核、公证后颁发数字证书，从而保证网络交易的安全可靠性。     

统一身份认证平台技术开发与应用

通过介绍信息系统中普遍存在的信息安全问题和普遍使用的身份认证技术,阐述了能够解决当前信息安全问题的、最先进的统一身份认证平台技术。它是基于动态令牌能够实现全程通信加密的、适用于对称和非对称加密算法的身份认证平台,并对非对称加密算法的数字签名加解密的完整过程用算法模型予以说明。平台在多个领域的实施效果不错,经检测是目前国内加密效果最好的统一身份认征安全管理平台。     

密码技术

密码技术是实现信息安全(Security)的基本要素。它的重要性越来越被人们所认识。本文以基本原理为中心对密码技术加以解说,并从现代观点对公用密钥加密方式、公开密钥加密方式、公开密钥分配方式、公开密钥数字签名方式以及置乱方式等几种加密体制加以整理和介绍。     

基于PKI的企业证书管理系统

概述 PKI公钥基础设施是一个为综合数字信息系统提供广泛需要的公开密钥加密和数字签名服务的基础设施,它的目标是管理密钥和证书。一个机构通过采用PKI框架管理密钥和证书可以建立一个安全的网络环境,使用户可以在多种应用环境下方便地使用加密和数字签名技术,从而保证网上数据的机密性、完整性、有效性。一个典型、完整、有效的PKI应用系统至     

数字加密安全技术研究进展及应用

本文通过梳理数字信息安全技术国内外研究文献,通过分析数字加密安全技术类型及重要意义,然后分析身份认证技术与数字签名,最后分析入侵检测安全技术研究进展及应用。为相关的数字安全技术理论与实践工作者提供基本的参考。     

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.     

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.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Call for Papers

正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its