基于OpenCL的HMAC-SHA256算法优化与实现

HMAC算法作为主流消息认证算法之一,面临着以纯软件方式运行速度慢,以传统的FPGA硬件实现方式更新维护困难的问题。针对上述问题,设计了HMAC-SHA256算法的定制计算架构并基于OpenCL以高层次描述方式进行了实现。具体包括计算路径优化、存储结构与查找表优化、HMAC-SHA256全流水结构设计。基于OpenCL的计算任务分组优化、数据存储优化、数据通道矢量化等手段实现了HMAC-SHA256算法的FPGA定制计算架构。实验结果表明：在Intel Stratix 10 FPGA平台上,所实现的HMAC-SHA256吞吐率达到174.236Gbps,与Intel Core I7-10700 CPU相比,性能提升了656%,能效提升了1514%;与NVIDIA GTX 1650 SUPER GPU相比,性能提升了14%,能效提升了288%。     

基于混沌映射的HMAC算法设计与分析

分析了HMAC（Hash-based Message Authentication Code）算法存在的固有缺陷,给出了针对HMAC参数的伪造攻击实例。在此基础上,提出了一种采用混沌映射的构造HMAC的算法,该算法通过混沌迭代生成HMAC参数值,混沌系统的初值敏感和不可预测性确保了参数值的动态性,从而有效抵抗伪造攻击,提高HMAC算法的安全性能。算法仿真与分析表明构造HMAC算法需要满足的安全性要求及嵌入的hash函数需满足的安全性条件。     

基于SHA-256的磁盘复制审计系统设计与实现

随着计算机和互联网络技术的迅速发展,电子数据鉴定的结论成为具有证据力的法定证据之一,文中介绍了电子取证中基于SHA-256算法的磁盘复制审计系统的设计与实现,在分析SHA-256算法的基础上,利用FPGA芯片实现了基于SHA-256算法的磁盘复制审计系统,提出了实现磁盘复制和生成SHA-256哈希值一种电路设计方案;利用SHA-256算法对DMA传输方式中的CRC校验码进行计算得到磁盘数据摘要,从而保证了采集数据的一致性,并且整个复制过程必须是可审计的;最后讨论了基于A1tera公司生产的StratixⅡ系列FPGA的实现结果。     

一种基于FPGA的可重构密码芯片的设计与实现

介绍了SHA-1、SHA224及SHA256三种安全杂凑算法的基本流程,采用可重构体系结构的设计思想和方法设计出一款可实现这三种算法的可重构密码芯片,并对关键路径进行了优化设计。最后给出了基于Altera公司的Cyclone系列FPGA的可重构密码芯片的实现结果。     

基于FPGA的SHA-256算法实现

本文分析了SHA-256算法的基本工作流程,对算法硬件实现的关键路径进行了优化设计,讨论了几个关键模块的设计方案。最后给出了基于Altera公司的CYCLONE系列FPGA的实现结果。     

Rijndael扩展算法及其FPGA实现

本文探讨了长度大于256比特明文和密钥的Rijndael密码扩展算法,提出了一种增强扩展密钥安全性的方法,介绍了Rijndael算法的FPGA模块的硬件实现。     

一种基于Hash函数和分组密码的消息认证码

基于Hash函数的HMAC是一种应用最为广泛的消息认证码,但最近的研究指出HMAC不仅易受到相关密钥攻击,在多用户环境下也易受到攻击.为了避免这些问题,我们对HMAC进行了改进,基于Hash函数和分组密码设计了一种新的消息认证码HBMAC.在分组密码是伪随机置换和Hash函数所使用的压缩函数是伪随机函数的基本假设下,使用共享随机函数模型证明了HBMAC的安全性.同时,还提出了HBMAC和HMAC的算法实现,并基于典型数据对两种算法的性质和效率进行了分析.结果表明,与HMAC相比,HBMAC在安全性和效率上取得了更好的折衷.     

HMAC认证协议的单片机实现

HMAC是一种基于密钥的Hash算法的认证协议,可以应用于电子商务领域。我们通过国有自 主知识产权的单片机ZQ032SA,实现了以MD5算法为核心的HMAC协议,并把它试用于IP电 话计费认证系统。     

HMAC认证协议的单片机实现

HMAC是一种基于密钥的Hash算法的认证协议,可以应用于电子商务领域.我们通过国有自主知识产权的单片机ZQ032SA,实现了以MD5算法为核心的HMAC协议,并把它试用于IP电话计费认证系统.     

ZUC-256流密码轻量级硬件设计与实现

ZUC-256是由中国开发的一种应对于5G通信和量子计算机的流密码,该算法主要包含ZUC-256流密码和一种基于该流密码的完整性算法（EIA3）。本文设计了2种不同的ZUC-256流密码轻量级电路结构,以及1种基于ZUC-256流密码的EIA3算法结构。基于FPGA对设计的电路结构和算法结构进行实现,并进行了性能对比。对比结果表明：本文设计的2种电路结构最高达到了6.72 Gb/s的吞吐率,相较于现有的ZUC-256电路设计在速度上提高了45.24%;本文设计的2种电路相较于之前的ZUC-128占用资源更少,在面积上分别减少38.48%和30.90%;本文设计的EIA3算法结构仅用0.71 μs即可对128位的数据进行加密。     

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.