一种基于新型USB Key的加解密系统设计与实现

目前,数据加解密系统的方式有很多,但通过USB Key硬件实现的还相对较少。该文主要介绍了一款新型USB Key加解密系统的设计与实现。大多数USB Key只能实现诸如身份识别这样的基础功能,而此USB Key在此之上加载了数据加解密系统。在加解密功能实现的过程中,当同时输入中英文时会产生数据编码的冲突。针对此问题,该文以ASCII码和GB2312码为基础进行了编码的改造。USB Key在数据加解密过程中使用的算法为RSA算法。     

一种抗窃听USB设备控制器

针对USB总线窃听问题,通过深入分析USB传输特性设计实现了一种抗窃听设备控制器。该设备控制器于接口电路与端点缓冲区之间嵌入分组密码模块与端点独立的序列密码模块,使得加解密能够在数据存取过程中透明进行且支持USB的全部传输方式与多管道应用。接口电路与密码模块设计支持流水传输,基本消除了加解密对端点缓冲区存取速度的影响。基于FPGA平台对其进行了实现,并结合Nios II片上系统与主机端软件进行了测试。测试结果表明该设备控制器能够正确地对总线数据进行加解密,可为各类外设提供抗窃听的USB通信能力。     

基于PDIUSBD12与单片机设计的智能USB软件狗

USB接口是一种通用串行总线,本文主要提出一种成本低的USB软件狗的设计方案,其中,介绍如何使用PDIUSBD12与单片机设计的智能USB软件狗的软硬件,还有USB软件狗这种技术的优点和软件狗与主机间的数据能够相互交换、软件狗的加解密的技术.     

数据库的加解密操作

FOXPRO数据库系统没有直接提供对数据库文件的加解密操作,而有时为了数据的安全可靠,应该对数据库文件加密和解密.由于FOXPRO系统提供了对文件进行低层操作的函数,本人利用FOXPRO系统这一功能编制对数据库文件的加密和解密程序.文中提供的加解密算法比较简单,只是表达一个加解密的思想,但是却非常实用.本人多次在编程过程中利用此程序对数据库文件进行加解密操作,基     

一种基于USB Key的双因子身份认证与密钥交换协议

传统的USB Key只能存储数据而无法进行复杂的加／解密运算,导致基于USB Key的认证协议存在诸多不足。本文针对含智能卡芯片的USB Key可进行加／解密运算和生成随机密钥的特点,提出了一种基于USB Key的双因子身份认证与密钥交换协议DKAKEP。该协议综合运用伪随机数验证、一次性会话密钥、AES加密算法、安全哈希算法等技术,除了可提供安全快速的身份认证与密钥交换,还具有快速更改密钥、支持多种哈希算法和无需时间同步机制的特点。 多种协议攻击,具有较强的实用性、安全性和可靠性。     

基于CY7C68013安全U盘的硬件设计

针对现存安全U盘的不足,提出了一款集数据加/解密、认证、抵抗攻击于一体的大容量安全U盘硬件设计方案,它能够较好地保护密算法和密钥的安全,在超期或非法操作超过一定次数时可自动销毁算法和存储的数据.从安全模型、结构模型等方面进行阐述,重点介绍了USB接口控制模块、数据加/解密、安全芯片操作等几个关键模块的开发,最后从策略、密钥安全等方面对此U盘的安全性进行了整体分析.     

安全移动办公平台技术研究

本文基于如何解决移动办公的安全性问题,提出了一套移动办公平台设计方柔。通过将操作系统以加密的形式存放在U盘,实现数据与操作的安全保密控制。计算机从USB接口启动加密型操作系统,办公过程中采用加密算法加解密所有流过USB接口的数据。平台通过Ukey提供USB接口认证与密钥,并采用USB通道加密和FPGA专用加密芯片等解决方案来满足处理性能需求。     

基于PNP自动映射分区的安全USB技术研究与实现

目前多数安全USB设备使用时,需要开启一个应用程序界面来对USB设备进行读写、加密/解密.对此,提出并实现了一种利用硬件PNP技术自动对USB映射为本地盘符,拔下时自动删除盘符的技术.读写文件时,对USB设备自动透明加解密;安全U盘使用前经过授权中心统一注册与授权,划分为权限注册区和加密区;用户密码验证采用基于密码的密码系统说明书(RFC2898)和应用伪随机函数导出密钥(PBKDF2);权限管理采用预先设定好的内、外网策略,内网策略分为多个等级.在实际应用中取得了较好效果.     

基于USB的加密视频客户端的设计与实现

针对USB无线视频实时接收装置的开发,论文介绍了在Windows视频客户端通过USB数据接口来接收数据,并且通过在Linux服务器端将采集的视频和音频数据加密,在客户端进行解密从而保证数据传输和存储安全性的设计方案.在客户端视频配置部分,特别定义了一个结构体和几种配置命令及类型来实现视频配置的功能.并且在本地播放部分设计了一个解密过滤器,来实现录制到硬盘上的文件的播放.此视频监控系统具有广阔的应用前景.     

一种高安全性的便携式USB存储加密系统

设计了一种高安全性的便携式USB存储加密系统。该系统基于嵌入式USB主机CH375设计,采用智能卡实现人机安全认证和密钥的安全存储,采用反熔丝型FPGA芯片AX250高速实现3DES算法,能够在完全脱离PC机的情况下对USB存储设备中的文件进行加解密,具有很高的安全性和整体性,并可满足野外或移动应用的需求。     

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。     

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.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).