基于身份签密的身份认证模型

身份认证方案是实现访问控制的重要工具.结合基于身份的签密思想和零知识协议,给出了一个身份认证方案模型,该模型可以实现通信双方的互认证,且可被任何一个基于身份的签密方案实例化.给出的实例化是以现存比较高效的一个基于身份的签密方案进行的.分析了实例化后方案的安全性,结果表明它可以避免重放攻击、伪造攻击、中间人攻击等常见攻击,且该方案可以容易地扩展为一个可认证的密钥协商方案.     

技术应用透视

身份直接认证5月25日获悉,兆维推出一款W-Key身份认证系统。这是一款基于对称密码方式的网络身份安全产品,结合了现代密码技术和智能卡技术,对网络用户与服务器之间直接进行身份认证,采用一次一密的加密作业方式变化认证码。该认证系统由W-Key、客户端软件和认证服务器端系统软件组成。客户端和认证服务器之间直接进行身份认证,通过USB接口与计算机连接,便于携带且操作简单,完全取代了“用户名+密码”这种模式。W-K e y身份认证系统的应用可以提高网络系统对用户身份的识别以及权限管理能力,只有W-Key的合法用户才可登陆网络。W-Key面…     

基于动态密码认证和VPN隧道的防水墙研究与实现

用户身份认证作为网络安全和信息安全的第一道屏障,目前防水墙认证主要采用传统的静态密码认证,在身份认证过程中易被窃取,严重危及企业内部信息安全.针对防水墙身份认证的安全需求,提出了扩展硬件身份及基于混沌理论的一次一密动态密码相结合认证,建立基于VPN的网络安全传输通道,实现了身份认证的无约定动态变化,增强了防水墙身份认证的安全性.     

网格环境下基于身份的跨域认证研究

在网格安全标准中,实体问的跨域身份认证采用基于证书的公钥基础设施认证框架,证书的管理过于复杂,限制了网格规模的扩大。针对上述问题,在分析网格安全需求的基础上,引入基于身份的密码体制,提出一种跨域签密方案,以解决使用不同系统参数的虚拟组织问相互认证的问题,并对其安全性和性能进行分析。     

云环境下基于签密的异构跨域身份认证方案

针对现有交互频繁的密码体制之间不能实现不同密码体制安全高效的跨域认证（公共密钥基础设施（PKI）↔无证书公钥密码体制（CLC））的问题,提出了一种云环境下基于签密的异构跨域身份认证的方法。该方法重新构建了异构系统跨域身份认证模型,设计了用户（U）与云服务提供商（CSP）两个不同的密码体制PKI↔CLC,去除所属域管理中心的跨域认证计算,引入了第三方云间认证中心（CA）来完成U和CSP的交互信息认证,采用签密算法对不同安全域内的U签密,完成了异构系统的双向实体跨域身份认证并降低了U的计算开销。实验结果表明,与匿名认证、代理重签名方法相比,所提跨域认证的效率分别提高了53.5%和23.2%。该方法实现了不同密码体制U身份的合法性、真实性、安全性,具有抵抗重放攻击、替换攻击和中间人攻击的功能。     

新型基于Chebyshev多项式的身份认证方案

对已有基于Chebyshev多项式的身份认证方案进行了安全性方面的分析, 引入密态时钟, 提出了一种新的身份认证方案。通过对其性能的研究, 新的方案是安全有效的。     

采用USB-KEY认证方式的安全平台设计

基于USB-KEY的身份认证方式是近几年发展起来的一种方便、安全、可靠的身份认证技术.它采用一次一密的强双因子认证模式,很好地解决了身份认证的安全可靠问题,并提供了USB接口与现今的电脑通用连接.本文应用USB-KEY的身份认证方式于PKI的网络安全平台当中,更好的解决了PKI平台中的密钥安全问题.     

一种基于签密的改进IKEv2协议*

针对IKEv2协议存在的对通信实体的身份保护不足和系统开销大等问题,提出了一种安全高效的改进的IKEv2协议.新协议采用了基于签密的可认证密钥协商来代替D-H密钥交换,在交换秘密信息的同时实现了对协议的发起者与响应者之间的双向认证;并且协议的响应者先主动证明自己的身份,确保了对发起者进行主动身份保护.基于认证测试方法对该协议进行形式化分析表明:新协议具有很好的秘密性和双向认证性;同时,该协议只需三条消息,具有简单、高效的特点.     

基于CFL的去中心工控系统签名认证方案

近来, 工业控制系统的身份认证和数字签名等安全问题受到越来越多的关注. 本文将去中心化的CFL认证体制引入到工控系统身份认证中, 提出了基于CFL的工控系统签名认证方案, 建立了基于CFL认证体制的工控系统认证模型CFL-SYS, 引入UKey作为证书载体, 实现了签名验证过程去中心化; 通过计算用户ID的哈希值生成随机私钥和标志私钥实现一人一密, 满足了用户对私钥的私有权并且保护了用户的隐私. 理论分析和实验结果表明, 本文方案在吞吐量、系统验证响应时间等性能上能够满足毫秒级应用需求, 能为大规模工业控制系统提供一种自主、可靠、高效的签名认证方案.     

ARM平台基于改进视觉密码认证系统的设计与实现

合法用户的身份认证在信息安全中起着非常重要的作用,以静态口令为基础的传统认证方式正面临多种安全隐患。基于视觉密码技术的原理和特点,从使用安全性方面提出改进算法,实现了一套完整的一次一密身份口令认证方案,使得认证过程更加安全可靠。系统采用双因素认证方式,将指纹识别技术和视觉密码技术相结合,进一步提高安全性,并最终在AM3517实验平台上实现。实测表明,该系统操作简单、认证过程安全可靠、易扩展、使用成本低,具有广阔的应用前景。     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.