一种超轻量级RFID双向认证协议

开放的无线通信环境,尤其是阅读器和标签间的无线信道,使得无线射频识别(RFID)系统的安全和隐私问题逐渐成为值得关注的焦点,因此设计抗各种恶意攻击和安全威胁的超轻量级RFID 认证协议是非常必要的。针对低代价标签提出了一种新的超轻量级RFID双向认证协议,该协议避免了已有RFID认证协议存在的安全隐患。安全分析表明新协议具有较强的安全和隐私属性,并且能够抵抗各种可能的恶意攻击。根据低代价RFID标签资源受限的需求,新协议仅需要在标签上执行两种简单的比特位操作,与其他超轻量级RFID认证协议相比具有更好的性能优势。     

基于公钥密码体制的RFID三方相互认证协议的研究

针对目前的RFID协议采用的认证和密码体制存在安全性问题及性能相对低下,提出一种基于快速NTRU(Number Theory Research Unit)密码体制的RFID三方相互认证协议。该协议首先将NTRU密码体制与异或等运算相结合从而实现服务器、阅读器及标签之间的相互认证,然后分析它的安全性及可行性,最后与其他相关认证协议进行比较分析。结果表明该协议能够为RFID系统在相互认证方面提供更高安全性及良好的性能表现,从而适应于低成本及效率较高的RFID标签。     

轻量级移动RFID认证协议研究设计

为解决移动射频识别（Mobile RFID）系统中信息通过无线信道传输所引发的安全与隐私问题,提出一种基于伪随机函数的轻量级移动RFID认证协议,实现后台服务器、阅读器与标签之间的双向认证。该协议中的运算主要集中在后台服务器和阅读器,可以有效地控制标签成本。安全性分析表明,该协议可以有效抵抗位置追踪、假冒、重放和同步化等攻击,并通过GNY逻辑进行了安全性证明。      

基于交叉位运算的超轻量级RFID认证协议

针对射频识别系统存在的安全隐患、标签成本较高等问题,提出了一种基于交叉位运算的超轻量级RFID认证协议(CURAP),并基于BAN逻辑形式化分析方法,证明了该协议的正确性与安全性。CURAP定义了交叉位运算,包含异或及左循环移位运算,且协议运行中,数据更新运算只在读写器中进行,而标签从传输消息中进行简单的异或运算提取即可。安全分析与性能评估表明,CURAP不但具有较强的双向认证性,能够抵抗多种攻击,而且可以有效降低标签的计算需求、存储空间,适用于低成本的RFID系统。     

基于随机数同步更新的RFID安全协议

针对无线射频识别(RFID)应用的安全问题,提出一种基于随机数同步更新的RFID安全协议。利用RFID后端系统生成的随机数实现标签认证,每次认证完成后对标签和随机数做同步更新。从理论上分析协议的执行性能和安全性,并利用BAN逻辑对协议的安全性进行形式化证明。结果表明,该协议能够实现标签和阅读器之间的相互认证,同时可抵抗重放、位置跟踪、流量分析、伪装、拒绝服务、非法读取等攻击。在实现上该协议仅使用哈希和异或运算,降低了标签的计算复杂性,适合低成本标签应用。     

一种改进的超轻量级RFID认证协议

针对当前超轻量级RFID认证协议中存在的安全缺陷,提出一种改进的超轻量级RFID双向认证协议。通过引入新的函数,使消息之间的数学关联性更加复杂,避免了泄露标签标识符,提高了阅读器和标签在开放环境中通信的保密性。对该协议的安全性和效率进行分析,并利用OPNET软件对该协议仿真实验,结果表明,该协议能抵抗代数攻击,重传攻击,假冒攻击等多种常见恶意攻击,在同等计算量下具有更高的安全性,可用于实际的移动身份认证环境。     

轻量级的无线射频识别安全认证协议

针对现有无线射频识别(RFID)认证协议存在的安全缺陷,提出了一种新的轻量级RFID安全认证协议,并基于GNY逻辑给出了形式化证明。协议采用阅读器双重认证及预认证阶段刷新密钥的方法,通过在标签中添加保护密钥同步的恶意攻击标记Tm,解决了当前协议中存在的可扩展性欠佳、标签密钥更新失败导致位置跟踪和非法更新标签/服务器内部密钥造成拒绝服务(DoS)等问题,可抵抗重传、标签/阅读器假冒和通信量分析等多种恶意攻击,尤其防范来自位置隐私泄露和拒绝服务的安全威胁。分析结果表明,所提协议具有低成本、安全性高、计算复杂度低等特点,适合于标签数目较多的RFID系统。     

RFID认证协议ULAP的被动攻击分析

无线射频识别(RFID)系统的双向认证机制可以有效地保护标签的机密性。对超轻量级RFID认证协议(ULAP)的安全性进行分析,结果表明,通过侦听多轮(预期值为10)阅读器和标签认证消息,就能推导出标签的全部秘密信息,因此ULAP协议不能抵抗被动攻击。     

EPC编码标签的RFID系统密钥无线生成

针对目前RFID系统的认证协议都是在事先设置好的共享密钥值基础上的,敌手可以通过一些手段获取密钥而对后续的认证造成安全威胁,提出了一种基于EPC编码标签的RFID系统密钥无线生成协议。将部分EPC加密进行通信,防止秘密信息泄露;引入标签与阅读器的安全模型,提高通信的安全性;阅读器随机数保持通信过程的新鲜性;仅采用异或运算降低标签成本与计算量。通过GNY逻辑对协议进行形式化证明,安全分析和性能分析表明,该协议符合安全模型并能够抵抗主动攻击和被动攻击,具有安全性高、低成本的特点。     

基于数字签名的轻量级RFID认证协议

RFID系统的安全和隐私问题已成为阻碍其进一步扩展的瓶颈。针对低代价标签提出了一种基于签名方案的轻量级RFID认证协议,它利用数字签名技术和RFID认证技术的恰当结合,成功实现了RFID系统的轻量级认证机制。性能评估表明新协议除了具有主要的安全隐私性能属性之外,还能够抵抗多种典型的恶意攻击和威胁,其安全性依赖于在有限域上求解离散对数问题的困难性和伪随机数生成器的安全性。新协议将公钥密码技术中代价较高的运算置于服务器端,确保了标签端运算的轻量性,促进了公钥密码技术在RFID系统中的进一步实施。     

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.