DES数据加密算法的VC程序实现

本文介绍了DES数据加密算法(Data Encryption Standard)的一般原理,同时对如何使用VC程序实现改算法作了阐述,并在DES原始算法实现的基础上(因为它一次只能加解密64位)进行扩充和改进,可以方便地加密/解密任何格式、任何大小的文件.     

.NET框架下DES加密/解密程序的实现

.NET框架提供许多标准加密／解密算法的实现。本文对．NET下加密／解密方法进行了详细的介绍，并通过DE-SCrypto Service Provider类实现DES加密／解密算法。     

DES加密算法在保护文件传输中数据安全的应用

随着Intemet的广泛应用,网络中文件传输的数据安全性越来越受到人们的重视。原始的DES加密算法一次加解密64位,本文介绍了如何使用C语言实现改进的DES数据加密算法,使其可以方便的加解密任意格式任意大小的文件,确保文件传输中的数据安全。最后针对DES加密算法存在的安全隐患给予了简单说明,并提出了DES加密算法的使用误区。     

基于WCF的DES数据加密设计与实现

WCF服务技术与DES算法相结合,通过对微软WCF服务技术分析及原理介绍,对WCF服务的设计、配置、使用DES类对WEB中数据实现加密与解密..NET Framework封装了DES加密类,为数据加密提供方便,DES算法高效可行,再利用WCF面向服务编程技术优点,应用WCF框架提供高效实用的DES加密解密服务,达到We...     

基于混沌离散模型的DES密钥生成算法研究

针对DES(数据加密标准)存在密钥过短、存在弱密钥等问题,本文在DES算法的基础上提出利用混沌离散模型的扩展DES密钥空间的改进思路,设计了一种基于logistic离散模型的DES算法。即用Logistic映射产生的混沌序列,构造DES的密钥,构成一个密钥空间,空间具有无限性且具有相互独立的特性。通过改进的DES算法对文本文档进行加/解密仿真,结果表明改进的DES算法实现了"一文一密"的加密方式,在安全性和抗攻击能力方面表现更优秀。     

DES算法中S盒的重组方法

DES算法是1972年美国IBM公司研制的对称密码体制加密算法,采用56位密钥长度,经过一系列的变换实现加密解密。但是自算法提出以来,面临着来自各方面的安全威胁,如穷举攻击,选择明文攻击等。本文分析DES算法的原理和特性,对原始算法提出有效的改进措施,在不影响算法加密效率的前提下,对提高DES的安全性和后续研究具有一定作用。     

DES与RSA算法的分析与研究

在现代加密技术中,DES算法以其实现速度快、密钥简短等特点而应用比较广泛,然而DES算法密钥本身的安全性又是一个问题;而RSA算法较好地解决了DES算法的密钥难于保管的难题,但RSA算法公钥算法比较复杂,解密速度慢的缺点也客观存在.将二者结合起来,用DES算法加密数据,使用RSA算法来加密对DES算法的密钥,在当前网络传输数据应用中,不失为一种好的措施.     

OES算法软件速度优化的实现

DES算法是银行过去常常使用的一种加解密算法，广泛地用于数据存取、交易保护和身份认证。尽管DES已经不再被认为是安全的加密算法，目前已经被逐步取代。但是由于目前硬件加密还无法覆盖小型机等大型系统，同时该算衍生出来的相关算法（如多重DES算法）至今仍被广泛应用，旧系统的数据转换仍然需要应用，因此DES类算法的软件优化在大型系统中仍然具备很高的借鉴价值。     

资源共享的并行AES加密/解密算法及其实现

随着密码分析技术的提高,原有的数据加密标准(DES)已经不能满足应用的要求.高级加密标准(AES)成为新一代的数据加密标准,取代了使用20多年的DES.目前的AES算法实现中普遍存在资源消耗大或者吞吐率低以及加密和解密分别实现的不足.为在资源消耗和吞吐率之问取得折衷,以资源共享和并行的方式同时实现AES加密和解密算法,分析AES算法中各个变换以及128位密钥扩展的性质和特点,选择复合域优化字节置换变换.推导结构简化列字节混合变换,提出128位加密/等效解密密钥扩展方案,同时实现了资源共享的并行AES加密和解密算法.通过在FTGA上的验证和与相关文献的比较,表明该方案以较少的资源获得了较高的吞吐率.     

基于DES算法的文件加密系统的设计与实现

随着互联网的普及,信息安全问题逐渐成为热点问题。DES算法,全称为数据加密标准,是一种对二元数据进行加密的算法,通过反复使用加密组块替代和换位两种技术,经过16轮的变换后得到密文,安全性高,在POS、ATM、磁卡及智能卡(IC卡)、加油站、高速公路收费站等领域被广泛应用。首先简要介绍了DES算法的原理和流程,分析设计了用VC++实现DES加解密的核心算法,在此基础上制作完成了一个文件加密系统。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。