Internet上电子邮件的安全机制

近年来，Internet用户已不满足于简单电子邮件．要求提供多用途的和安全的电子邮件，为此出现了MIME，PEM，PGP和MOSS，S/MIME，PGP／MIMF，MIMEWithMSP等多种方案、本文综述了这些方案，尤其对安全机制进行了详细的讨论。     

关注商业版PGP7．0的新功能

继PGP6．＊版本之后美国网络联盟公司（NAI）又推出了PGP7．0版。除了在操作界面和加密算法上做了改进外，新版PGP的突出特点是新增了Gauntlet自适应网关代理防火墙、Cybercop入侵检测、PGP VPN和电子商务服务器。新版PGP使该网络密码软件的功能由传统的数据信息保密上升到数据信息保密和网络系统安全两大方便，使PGP这朵绚丽的网络密码之花又添异彩。     

基于模糊值Choquet积分定义集函数的S性与PGP性

针对模糊测度空间上已建立的模糊值Choquet积分,将这种积分整体看成可测空间上取值于模糊数的集函数,当模糊测度满足一般S性和PGP性时,研究了这种模糊值集函数所保持的遗传性质.     

电子邮件安全威胁与防护技术研究

随着Internet的迅速发展,电子邮件以其方便、快捷的特点成为人们进行信息交流的重要手段,利用电子邮件进行通信的需求正以惊人的速度增长。在电子邮件应用过程中出现了针对电子邮件的威胁和利用电子邮件作为传播手段的安全威胁,论文在分析这些威胁的基础上,提出并分析了相应的安全解决方案。     

π‐Plasmon absorbance films of carboxylic functionalized CNTs coupled with renewable PGP platforms

π‐Plasmon absorbance films of carboxylic functionalized multiwall carbon nanotubes (CNTs) coupled with renewable and recycled polycaprolactone grafted pectin (PGP) platforms as successful alternative for ordinary nondegradable platforms were investigated. Characterization of the synthesized carboxylic functionalized CNTs was performed using ¹H NMR and attenuated total reflectance Fourier transform infrared for structural identification, thermogravimetric analysis and derivative thermogravimetric analysis for thermal stability, and X‐ray powder diffraction for crystal structure, whereas the characterization of prepared PGP was done by means of attenuated total reflectance Fourier transform infrared for chemical structure, differential scanning calorimetry for melting endotherms of polycaprolactone and high crystalline structure of PGP, and thermogravimetric analysis and derivative thermogravimetric analysis for thermal stability of PGP. Fabrication of water‐dispersed carboxylic functionalized CNTs coupled with PGP films was performed by casting technique in the presence of Ca²⁺ as cross‐linker. The thin films were tested for π‐plasmon absorbance using UV‐Vis spectrometry. Different fractions of carboxylic functionalized CNTs and PGP films demonstrated π‐plasmon absorbance broad peaks at λ_max = 232 nm, which corresponded to 5.36 eV. The fabrication of novel films from renewable recycled PGP platform and advanced carboxylic functionalized CNTs properties will be the key features for many of next forthcoming technologies. The PGP considered as environment‐friendly and easily degradable platforms will be a successful alternative for conventional nondegradable electronic platforms, and water‐dispersed carboxylic functionalized CNTs with advanced properties will be finding accelerating executive applications.     

棱镜-光栅-棱镜分光模块整体化设计及衍射特性分析

PGP模块是超光谱成像仪中重要分光器件。为了能够在制作前有效预测PGP整个系统的衍射效率分布及其衍射特性,提出了PGP整体化设计方法。从体位相全息光栅设计角度出发,结合棱镜与光栅各项参数的制约关系,编制了计算PGP整体衍射效率的分析软件,综合考察了棱镜与光栅各项参数对PGP模块衍射特性的影响,讨论了光栅布拉格波长的漂移特性,据此设计了一种用于成像光谱仪的宽波段高衍射效率PGP分光模块。模拟结果表明：棱镜1材料的色散系数越小,PGP的光谱带宽越窄;光栅布拉格波长的漂移增大了PGP模块和光栅的光谱带宽,带宽增大使光栅的角度选择性随之增大,拓宽了棱镜1材料的选择要求;棱镜1顶角、光栅的胶层厚度和相对介电常数调制度等参数是影响PGP衍射效率分布的重要因素,制作时需要精确控制。利用此方法设计的PGP分光模块在400～1 000 nm波段范围内衍射效率不低于50%,并给出具体设计参数,这对PGP制作具有一定的参考价值。     

基于PGP的动态连接库与U盘构成的安全认证系统

利用PGP提供的动态连接库以及U盘的特点,提出了一种电子文档的加密与认证系统,并讨论了相关算法和流程。     

未来战地网络的安全体制

战地网络容易受到攻击和破坏,如何实现未来战地网络中的安全通信是一个亟待解决的问题。提出了一种支持未来多层无线异构adhoc战地网络安全通信的安全体制,它具有如下性质:(1)可以在有/无基础网络设施模式下工作并无缝切换;(2)采用集中式CA签名和(t,l)门限签名体制相结合的认证方法;(3)对报文和报头分别加密;(4)可以对签名者的身份进行追踪。     

Portfolio selection with skewness: A comparison of methods and a generalized one fund result

This contribution compares existing and newly developed techniques for geometrically representing mean–variance–skewness portfolio frontiers based on the rather widely adapted methodology of polynomial goal programming (PGP) on the one hand and the more recent approach based on the shortage function on the other hand. Moreover, we explain the working of these different methodologies in detail and provide graphical illustrations in relation to the goal programming literature in operations research. Inspired by these illustrations, we prove two new results: a formal relation between both approaches and a generalization of the well-known one fund separation theorem from traditional mean–variance portfolio theory.     

安全电子邮件相关技术的研究

随着Ｅ－ｍａｉｌ在Ｉｎｔｅｒｎｅｔ上的广泛应用，其安全性越来越受到关注。电子邮件的安全问题，主要可以分为两个方面，即邮件内容的安全（Ｍｅｓｓａｇｅ Ｓｅｃｕｒｉｔｙ）和邮件传输的安全（ＴｒａｎｓｍｉｓｓｉｏｎＳｅｃｕｒｉｔｙ）。从这两个方面着手，研究电子邮件安全体系的相关技术，并对它作分析比较，最后结合实验结果，给出了一个可行的安金电子邮件系统的设计框架。