Effects of Aliasing Errors on Microlithographic Image Computations

Recent advances in computational microelectronics have made it possible to compute the images of very large masks. Images of entire masks require many gigabytes of storage. It is therefore desirable to make storage requirements as small as possible. In this paper, we investigate the effects of reducing resolution to the point where some aliasing error enters the final answer. Due to the accuracy requirements of the microelectronics industry, we conclude that reducing resolution to improve storage requirements is not feasible.     

Aliasing assessment in wavelength domain of hyperspectral data

This paper focuses on a procedure for the assessment of spectral aliasing in hyper-spectral data acquired by push-broom spectrometers. The procedure is based on a push-broom spectrometer model that simulates acquired spectra by taking into account only the instrument parameters; aliasing is measured by means of some figures of merit considered among those proposed in literature. Quantitative evaluations have been performed on simulated spectra both with and without ideal atmospheric and radiometric correction. Results are presented in this paper; the impact of spectrometer slit size on aliasing appearance is also addressed.     

Measuring Errors in Operational Analysis Assumptions

Operational analysis, an area of study first defined in the computer science field, has been used in the analysis of systems performance. System performance measures for a specific set of output data are obtained using operational analysis formulas derived from assumptions which are verifiable by the observed data. This paper gives relationships which may be used to quantify the errors in these assumptions. Additionally, basic propositions are given which help in understanding operational analysis assumptions. These propositions are used in developing correction terms which can be used to adjust performance measures so that their values are exact for a set of data no matter how much the assumptions used in deriving the performance measure relations are violated.     

群签名方案的效率分析

自1991年群签名的概念由Chaum与vanHeyst提出以来,群签名因其显著的特性引起人们的广泛关注。许多群签名方案及基于群签名方案的密码协议被提出。但是,群签名方案的效率是一个棘手问题。为使群签名同时具有匿名性与可追踪性(发生争议时可打开),群签名的执行效率往往比较低下。因此,群签名方案的效率分析便成为一个令人感兴趣的课题。该文对3个典型群签名方案进行了效率分析。结果显示,Ateniese等人在CRYPTO’2000上提出的群签名方案具有较为优越的效率与安全特性,以该方案为基础构造各种密码协议可能会达到较好性能。     

电子商务中的椭圆曲线数字签名算法分析

电子商务的安全性随着电子商务的发展越来越重要。椭圆曲线数字签名是用来保证电子商务安全的技术,在实现身份认证、数据完整性和不可抵赖性等功能方面都有重要作用。椭圆曲线数字签名为电子商务安全问题提供一个新的参考,主要探讨电子商务中椭圆曲线数字签名算法分析。     

Aliasing and adversarial robust generalization of CNNs

Many commonly well-performing convolutional neural network models have shown to be susceptible to input data perturbations, indicating a low model robustness. To reveal model weaknesses, adversarial attacks are specifically optimized to generate small, barely perceivable image perturbations that flip the model prediction. Robustness against attacks can be gained by using adversarial examples during training, which in most cases reduces the measurable model attackability. Unfortunately, this technique can lead to robust overfitting, which results in non-robust models. In this paper, we analyze adversarially trained, robust models in the context of a specific network operation, the downsampling layer, and provide evidence that robust models have learned to downsample more accurately and suffer significantly less from downsampling artifacts, aka. aliasing, than baseline models. In the case of robust overfitting, we observe a strong increase in aliasing and propose a novel early stopping approach based on the measurement of aliasing.

     

The Case for Polymorphic Registers in Dataflow Computing

Heterogeneous systems are becoming increasingly popular, delivering high performance through hardware specialization. However, sequential data accesses may have a negative impact on performance. Data parallel solutions such as Polymorphic Register Files (PRFs) can potentially accelerate applications by facilitating high-speed, parallel access to performance-critical data. This article shows how PRFs can be integrated into dataflow computational platforms. Our semi-automatic, compiler-based methodology generates customized PRFs and modifies the computational kernels to efficiently exploit them. We use a separable 2D convolution case study to evaluate the impact of memory latency and bandwidth on performance compared to a state-of-the-art NVIDIA Tesla C2050 GPU. We improve the throughput up to 56.17X and show that the PRF-augmented system outperforms the GPU for \(9\times 9\) or larger mask sizes, even in bandwidth-constrained systems.     

一个群签名方案的安全性分析

对李继国等提出的群签名方案(电子学报,2011年第7期)进行分析,发现在该方案中,群管理员可以得到所有群成员的私钥,从而伪造任意群成员的签名,并且攻击者可以轻易伪造任意消息关于任意群成员的有效群签名,导致方案可被普遍伪造.在此基础上给出2个伪造攻击方法,证明群成员的签名可以被包括群管理员在内的任何敌手伪造,因此该方案不满足可追踪性,在标准模型下是不安全的.     

两个群签名方案的安全性分析

群签名在电子现金、电子选举等领域有着广泛应用,因此基于不同的数学问题设计安全高效的群签名方案有着重要意义。对最近提出的一个基于中国剩余定理的群签名方案和一个基于RSA签名的群签名方案进行研究,发现这两个方案存在安全漏洞:第一个方案中,任何一个群成员均可以分解系统模数,从而可以计算出系统中所有人的私钥;第二个方案的群签名打开算法不正确,从而无法追踪到群签名的生成者。分析表明,这两个方案均是不安全的,需要进一步完善。     

浅析数字签名在电子政务中的应用

分析数字签名的功能、原理及其与传统手写签名的差别,对基于身份的数字签名进行了探讨,给出了数字签名在电子政务中的具体应用。     

数字签名在OpenType字库中的分析研究

介绍了数字签名的方法和过程,分析了OpenType矢量字库的表结构和与数字签名相关的表的内容。结合数字证书技术,应用于OpenType矢量字库上,将数字签名嵌人字库表中。给出了基于Windows平台的字库数字签名的具体实现步骤和结果的验证过程,完成数字签名的计算和写入。将此技术应用于字库生产过程中,实现了字库的完整性、安全性、真实性和可信性,收到了良好的效果。     

On the Signature Tree Construction and Analysis

Advanced database application areas, such as computer aided design, office automation, digital libraries, data-mining, as well as hypertext and multimedia systems, need to handle complex data structures with set-valued attributes, which can be represented as bit strings, called signatures. A set of signatures can be stored in a file, called a signature file. In this paper, we propose a new method to organize a signature file into a tree structure, called a signature tree, to speed up the signature file scanning and query evaluation. In addition, the average time complexity of searching a signature tree is analyzed and how to maintain a signature tree on disk is discussed. We also conducted experiments, which show that the approach of signature trees provides a promising index structure.     

一个门限数字签名方案的分析

对新近出现的一个典型门限数字签名体制进行分析，成功地对该方案进行了合谋攻击，从而证明了该方案是不安全的，同时，还讨论了该方案的其他弱点。     

两个群签名方案的安全性分析

群签名在电子现金、电子选举等领域有着广泛应用，因此基于不同的数学问题设计安全高效的群签名方案有着重要意义。对最近提出的一个基于中国剩余定理的群签名方案和一个基于RSA签名的群签名方案进行研究，发现这两个方案存在安全漏洞：第一个方案中，任何一个群成员均可以分解系统模数，从而可以计算出系统中所有人的私钥；第二个方案的群签名打开算法不正确，从而无法追踪到群签名的生成者。分析表明，这两个方案均是不安全的，需要进一步完善。     

典型代理签名方案的分析与改进

简述了代理签名及其应用的研究成果和发展状况,分析了现有的、对学科发展有重要意义的几个典型代理签名方案,指出其中存在的一些缺陷,给出了Lee方案的一个改进方案。该方案克服了Lee方案的弱点,满足强不可伪造性。该文还提出了这方面研究目前所存在的问题及几个值得重视的研究方向。     

数字签名技术分析与研究

介绍了公钥体制及数字签名技术,具体分析了多点对一点的群数字签名方案,最后给出了为适应Internet通信安全新需求而出现的数字签名方案.     

基于特征分析的网络入侵检测技术比较

文章论述了基于特征分析的网络入侵检测技术的三种方法:模式匹配、协议分析和状态协议分析,分析了它们的工作原理。并通过包括SYNFlood、拒绝服务攻击、Nimda病毒和FTP缓冲区溢出等攻击实例详细说明他们不同的解决问题能力。     

数字签名技术分析与研究

本文介绍了数字签名的概念、分类及原理,具体讲述了RSA数字签名方案和ELGamal数字签名方案,并对这两种经典的数字签名方案进行了相应的数学描述.在此基础上指出两种方案的缺陷以及与之对应的解决方法.对数字签名应用过程中可能遇到的安全性问题进行阐述,给出预防签名方案被攻击的基本安全需求.最后,指出了数字签名今后的主要研究方向及最新研究动态.