基于混沌理论的身份认证方案

基于混沌理论和一次性口令认证技术, 提出一种可以抵御常见攻击的身份认证方案. 解决了常规一次性口令认证方案不能抵御小数攻击、 明文传送迭代次数不安全以及传统Hash函数存在易于找到碰撞安全漏洞的问题, 该方案用混乱和散布性质好、 抗碰撞能力强的混沌Hash函数代替传统的Hash函数, 用混沌置乱排序算法产生的迭代次数代替网上明文传输的迭代次数, 具有较高的安全性.     

云环境下基于PKI的一次性口令身份认证系统设计

当前身份认证系统口令设计过程复杂,不仅容易出现认证错误的现象,而且大大增加了计算复杂度,影响整体性能。为此,提出一种新的云环境下基于PKI的一次性口令身份认证系统,给出设计系统总体结构,其主要由CA证书服务模块、RA注册模块、认证模块与用户模块构成。身份认证选用用户数字证书与一次性口令相结合的形式,对用户名与一次性口令进行验证时,通过用户名得到其数字证书,利用“挑战-应答”协议判断用户是否合法。介绍了一次性口令生成技术,给出公开大素数与保密大素数的确定过程。实验结果表明,采用所设计系统对云环境下用户进行身份认证,不仅认证精度高,而且整体性能强。     

云环境下公钥基础设施的一次性口令身份认证系统设计

当前身份认证系统口令设计过程复杂,不仅容易出现认证错误的现象,而且大大增加了计算复杂度,影响整体性能。为此,提出一种新的云环境下基于PKI的一次性口令身份认证系统。给出设计系统总体结构,其主要由CA证书服务模块、RA注册模块、认证模块与用户模块构成。身份认证选用用户数字证书与一次性口令相结合的形式,对用户名与一次性口令进行验证时,通过用户名得到其数字证书,利用"挑战-应答"协议判断用户是否合法。介绍了一次性口令生成技术,给出公开大素数与保密大素数的确定过程。实验结果表明,采用所设计系统对云环境下用户进行身份认证,不仅认证精度高,而且整体性能强。     

基于Web服务的使能服务平台安全机制

介绍了一个在网络经济模式下,基于Web服务的、支持中小企业动态联盟的使能服务平台,并分析了其中面临的安全威胁,提出了一套适用该平台的安全机制·该安全机制可以为用户提供信息通信保密,访问权限控制,数字签名,身份认证,密钥管理以及入侵检测等安全性保障·其中使用了AES和混沌密码算法进行数据加密,RSA算法用于数字签名和密钥交换,Guillou Quisquater协议用于身份认证,一个基于RSA的秘密共享体制保存密钥·在入侵检测系统中,综合使用了神经网络,数据挖掘和计算机免疫方法·最后,分析了其安全性·     

混沌理论在网络安全中的应用

基于混沌理论的网络安全技术采用一次性口令的双因素企业级网络访问认征，重点是网络口令的确认，并结合服务器端，其他安全授权等。系统工作于客户机/服务器模式，由“认证服务器”和“电子令牌”组成，具有身份鉴别，安全审定，非法登录报警等功能，是传统网络安全产品强有力的助手，是网络安全的重要工具。     

基于SAS-2的新型一次性口令认证方案

本文首先对典型的S/KEY口令序列认证方案的基本原理、实现方式进行了简单说明,通过研究该认证方案的工作过程和分析其安全性,指出其认证方案中所存在的安全缺陷。在综合S/KEY口令序列认证方案和SAS-2认证方案的基础上,本文提出了一种新型的一次性口令认证方案——NOTP(NewOne-TimePassword)认证方案。NOTP认证方案具有认证步骤简单、执行性能优异、无需重新初始化等特点。同时,NOTP认证方案还增强了抵御各种针对一次性口令认证方案攻击的能力,安全性得到了提高。     

基于一次性口令和椭圆曲线密码体制的移动商务身份认证协议设计与研究

移动商务的身份认证问题已成为制约移动商务发展的瓶颈.一次性口令技术实现简单、成本低、无须第三方认证的特点使其较适合移动商务的身份认证.通过椭圆曲线密码体制实现数字签名和密钥协商,提出基于一次性口令和椭圆曲线密码体制的移动商务身份认证协议,并利用串空间方法证明协议的安全性.     

车载控制器局域网络总线的动态口令身份认证方法

针对车载控制器局域网络(CAN)总线存在缺陷、严重威胁车载信息安全的问题,提出了一种基于挑战/应答模式的车载CAN总线动态口令身份认证方法。该方法考虑到CAN总线是使用极为广泛的标准车载总线及广播形式发送消息的特点,通过利用身份认证技术来确认消息的身份,保证了总线上消息传输的可信任性;根据对身份认证实现模式的研究,采用基于挑战/应答模式的动态认证方法,由于每次认证的挑战值都是随机的,因此每次生成的口令都是不同的;在每次通信时,所使用的认证码都是根据口令生成的,并通过哈希函数生成下次使用的口令。实验结果表明,与传统的CAN总线的方法相比,使用该方法后可以在保证CAN总线真实性的同时,保证传输消息的完整性,从而大幅度提高了车载信息安全级别。     

一种安全的两方口令认证的密钥交换协议

对于口令认证密钥交换协议的服务器泄漏伪装攻击,提出一个针对该攻击的两方口令认证的密钥交换协议,并分析了该协议的安全性。所提出的协议中,用户保存自己的口令明文,服务器存储用户口令明文的验证值,用户和服务器之间通过身份标识和含有口令验证值的信息来认证对方。分析表明,所提出的协议是安全的。     

中间多比特量化混沌扩频序列及其性能分析

利用伪随机数生成技术,提出了一种具有较好独立性与相关性的新的混沌序列中间多比特量化方案·研究了中间多比特量化方案产生扩频序列的平衡性和奇、偶相关性等与扩频系统性能相关的因素·仿真结果表明该方案在保持扩频序列性能不变的同时减少了序列生成的运算量,扩展了扩频序列周期,增加了序列的复杂度,有利于提高扩频通信系统的安全性·     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that