IPSec协议及其安全性分析

介绍和分析了网络层安全协议 ( IPSec) ,并侧重研究了其认证和保密两种安全机制 ,对有关 IPSec协议安全性问题进行了较为详细的分析 ,指出了 IPSec协议的实际应用价值     

金山WPS加密文件的解密

本文在实践的基础上,通过对WPS加密文件加密机理的探索,找到了其解密的实用方法,并以C语言编制出了解密的实用程序,为用户的文本编辑操作免除了不必要的麻烦。     

一种隐含加密子目录的新方法

给出了一种隐含加密子目录的新方法。     

单话机多用户电话加密计费系统

叙述了一种知机多用户电话加计旨系统，它可以自动识别脉冲，双音频信号，监失电话拨号，分别对国际，国内以及市话进行分组加密及计费。     

基于MIS菜单项的加密算法

本文介绍了如何在管理信息系统的菜单项上实现加密的算法.     

Applesoft中使用监控指令的进一步探讨

Applesoft中,直接使用监控指令与机内对话将极大地扩展BASIC的功能。这里就调用键盘缓冲区扫描子程序的方法及其所带来的问题作了进一步探讨,并给出一种较直观的解决方法。     

看数轴写程序VF6．0中双向分支及其嵌套的教学

本文介绍用数轴方法辅助教学VF6．0中的双向分支及其嵌套。     

噪音对光学图象浑沌相位列阵加密和解密的影响

本文提出了一种用浑沌相位列阵对光学图象加密和解密的方法,并重点分析了加法高斯白噪音对光学图象浑沌相位列阵加密和解密的影响.通过计算机模拟发现加密后的图象与原图象相比,抗振幅噪音的能力增强,而抗相位噪音的能力下降.在一定信噪比范围内,相位噪音是影响解密图象质量的主要因素.     

Small Transitive Families of Subspaces

A family of subspaces of a complex separable Hilbert space is transitive if every bounded operator which leaves each of its members invariant is scalar. This article surveys some results concerning transitive families of small cardinality, and adds some new ones. The minimum cardinality of a transitive family in finite dimensions (greater than 2) is 4. In infinite dimensions a transitive pair of linear manifolds exists but the minimum cardinality of a transitive family of dense operator ranges or norm-closed subspaces is not known. However, a transitive family of dense operator ranges with 5 elements can be found, and so can a transitive family of norm-closed subspaces with 4 elements. In finite dimensions (> 1) three nest algebras (corresponding to maximal nests) can intersect in the scalar operators, but two cannot. It is not known if this is the case in infinite dimensions for maximal nests of type ω + 1. Four such nest algebras can intersect in the scalar operators. Received June 15, 2002, Accepted November 27, 2002