基于大随机数的字符串加密算法设计与实现

分析了基于大随机数的字符串加密算法原理,给出了一个具体的加密、解密算法并利用VFP实现。利用该算法对一个具体实例进行了加密,实验结果表明,基于大随机数的字符串加密算法完全可以满足VFP数据库应用系统保密的要求。     

基于混沌加密算法的VFP文件加密

由于Logistic映射具有初始条件敏感性、随机性、相关性等优良的密码学性能而广泛应用于混沌加密。本文分析了基于Logistic混沌映射的加密算法原理;给出了一个基于该算法的具体加密解密算法;并将已设计的加密算法应用于VFP数据库中的字符串加密和文件加密。     

Gost加密算法

本文介绍了Gost加密算法,给出了在Visual FoxPro 8.0/9.0中实现字符串数据加密、解密的程序代码.     

Gost加密算法

本文介绍了Gost加密算法,给出了在Visual FoxPro 8．0／9．0中实现字符串数据加密、解密的程序代码。     

基于C++的保密文件加密处理设计

分析数据加密技术中的置换算法及其加密解密指导思想,给出加密解密置换算法的程序设计方法与具体实现步骤,并提供一个完整的加密解密算法的C++源程序。     

图像双重加密方法

介绍了在Visual Basic下使用用户口令字符串产生的伪随机数序列和图像中各像素点的二进制位数组,采用Xor运算和位移运算两种加密方法进行图像加密的原理及其实现方法,将加密、解密变换建立在二进制位数组基础上,实现了完整的图像加密、解密程序.     

Visual Basic下图像双重加密方法的研究与实现

介绍了在Visual Basic下使用用户口令字符串产生的伪随机数序列和图像中各像素点的二进制位数组,采用Xor运算和位移运算两种加密方法进行图像加密的原理及其实现方法,将加密、解密变换建立在二进制位数组基础上,实现了完整的图像加、解密程序。     

图像加密预览算法

针对解密一个加密图像耗时长的问题,基于混沌帐篷映射加密算法提出一种图像加密预览算法。算法首先采用图像识别与图像分割技术选择图像关键区域或采用图像缩略图技术生成原图像的预览图像;然后利用混沌帐篷映射加密算法分别对原图像及其预览图像进行加密;最后将加密后的原图像和预览图像进行整合生成加密图像。该算法在解密原图像前先解密预览图像,实现加密图像预览功能。实验表明,该算法可以对加密图像进行解密前预览,预览效果好,耗时短。     

分组密码IDEA的FPGA实现

根据IDEA密钥扩展方式和加解密流程,采用FPGA技术,对IDEA的功能模块进行了划分和设计,重点介绍了该文中所设计的关键功能模块的实现方法.给出了Verilog语言编写的实现该算法的关键性源代码.最后,对该IDEA算法加/解密模块进行了较全面的测试及性能分析.理论分析和仿真的结果表明,该模块能够准确实现加密和解密.     

多功能AES加密与解密软件的设计与实现

文章将AES算法应用于对字符串与文件的加密与解密,并提出了＂加密包＂的概念。在对AES算法实现时,采用了预先计算查找表、密文挪用等技术,使该算法的运行更加快速且合理地解决了等处理数据长度不是数据块分组长度的整数倍这一特殊情形;在对文件读写的优化实现上采用了多线程、多缓冲区及内存映射文件三种技术相结合的方式,极大地提高了软件的文件读写效率。实验结果表明,该软件具有很高的运行效率且操作灵活便捷。     

一种基于DES和RSA的数字签名方案

本文分析DES加密算法和RSA签名算法。作者采用DES算法和RSA算法相结合的密码方案,引用摘要,提出了一种基于DES和RSA的新的数字签名方案,并给出了它的应用实例。     

基于MPC8379E加密NAS的设计

介绍了NAS的工作原理与优点,根据网络存储实际应用中的安全隐患,提出了加密NAS的应用需求.研究了以MPC8379E为主控芯片的AES加密NAS的解决方案,并详细论述了NAS加密密钥管理的实现方法.该方案能够很好地实现加密NAS的访问控制与算法密钥管理,保证了数据加密存储的安全性.     

Automated String Constraints Solving for Programs Containing String Manipulation Functions

The ability to solve various constraints is a principal factor of automatic constraint solvers. Most object-oriented languages treat a character string as a primitive data type which is manipulated by string library functions. Most constraint solvers have limitations on their input constraints, such as strong restrictions on the expressiveness of constraints or lack of the ability to solve hybrid constraints. These limitations hinder applying automated constraint solvers on program analysis techniques for programs containing strings and string manipulation functions. We propose an approach to automatically solve program constraints involving strings and string manipulation functions. Based on the character array model, we design a constraint language which contains primitive operations to precisely describe the constraints of commonly used string manipulation functions. The translated string constraints together with numeric constraints are then solved by a two-phase test generation procedure: firstly, a partial solution is obtained to satisfy the arithmetic constraints of the position variables, and the solution is utilized to simplify the string constraints into pure character array constraints; secondly, the pure array constraints are solved by an off-the-shelf array-specific theory based constraint solver. We integrate the approach into an automated testing tool to support the generation of string test cases, and then perform experiments. The results of the experiments prove that the integration of the proposed approach promotes the testing coverage of the existing testing tool, and the integrated tool has an advantage of handling specific string manipulation functions compared with an existing string solver.     

动态网页源码安全性研究及实现

本文在研究了动态网页源码特性的基础上,针对动态页面的源码安全性特点,设计了在开发动态页面的过程中如何加密源码的方法,即将动态页面编译后要向客户显示的内容保存在相应的字符串变量,将其加密,并自动生成静态文件,最后用页面自动跳转的方法将动态页面跳转到该静态页面,以保护源码的安全.     

超混沌强化对称加密算法的研究与应用

混沌系统对初始值的极端敏感,使得它呈现出类随机性和数据难以预测的特点,因此在安全通信和算法加密设计方面得到了许多应用.数字签名技术是网络信息传输过程中经常应用的加密技术,不同于多数系统中经常采用的非对称加密技术,提出了一种基于超混沌强化对称加密算法的数字签名技术,通过对DES算法的入口参数进行混沌加密,而使得对称算法得到了进一步的增强,给出了数字签名算法的实现过程并给出了该方法在局域网信息安全传输中的应用.     

Coding schemes variation and its impact on string hashing

This paper presents the results of investigating the impact of variations found in character coding schemes on the performance of string hashing. The investigation involved three types of Arabic strings (single words, personal names, and document titles) and four different Arabic coding schemes. The results were examined in three different respects: collision rates, arithmetic code redundancy, and the contribution of arithmetic redundancy to the collision rate. Two items are considered arithmetically redundant, if they have the same numerical coding value. Even though the mathematical properties of coding schemes showed some impact on the hashing results, coding scheme variation was basically reflected in the results of hashing on single dictionary words. Where a difference was noted in the rates of arithmetic redundancy, it was accompanied by different growth patterns of collision. The results seem to indicate that the arithmetic properties of the collating sequence of a given coding scheme are likely to have some impact on the performance of string hashing.     

Portable Character Processing in Fortran and Fixed Integer Environments

Many languages, including Fortran, and machines such as most minicomputers have little or no built-in character manipulation capability and yet are often required to process character information. This paper discusses the programming of character processing in such integer environments. Character representation, string-to-word coordinate transformation, packing, and unpacking using several arithmetic schemes are discussed with special attention to program portability. Several Fortran subroutines are presented culminating in BYTRAN, a set of portable Fortran subroutines that simulate the string structures and operators of the PL/I language.     

随机数在保密传输中的应用

当今世界已经是信息的世界,有了信息就有了交换,在Internet已经得到了广泛普及的今天,信息的保密传输还是Internet中的一个难题。于是便产生了数据加密,有了加密就肯定有解密,加密和解密是层出不穷的。作为现在流行的采用密钥加密解密的算法,无非分为对称密钥和非对称密钥两种类型。本文将着重讨论一下利用随机数作为密钥,采用现有的加密技术达到比较高的数据传输的保密性。     

用三重DES加密.NET数据库连接字符串

南航网上售票系统基于微软的.NET技术,数据库连接信息存放在Web.config配置文件中.通过使用3DES算法对数据库连接字符串进行加密,增强系统的安全性.首先分析.NET Framework提供的密码类,然后设计了具体的3DES的应用类.管理员设置数据库连接信息,并用3DES加密后,放置于Web.config配置文件中.应用程序从Web.config中取出连接字符串,解密后,用其创建ADO.NET数据库连接.