主动网络安全机制研究

主动网络的安全性包括对主动分组和主动节点的保护，对主动节点的保护是在通过认证的基础上，参考策略库对不同的分组授予不同的节点资源访问权限来实现。主动分组在传输过程中的代码的可靠性和完整性可以通过加密和数字签名加以保证，而在主动节点上的安全性主要通过节点和分组的双向认证及接口的严格定义，分组间的隔离及对分组的必要限制等来实现。     

一种适用于Ad hoc网络的轻量级密钥交换协议

通过对Ad hoc网络安全性特殊需求的分析,提出适合其特点的轻量级节点间密钥交换协议. 协议使用一种新的基于ID的身份认证机制相互验证身份;使用改进的Blom机制生成加密密钥和认证密钥,分别用于数据私密性保护和报文完整性检查. 为了防止敌方捕获密钥,提出基于节点间数据流的密钥更新机制. 针对节点撤销,给予相应的解决方案. 从不同的角度对协议进行安全性分析,通过和其他实现方法比较,在性能方面证明其高效性.     

通用的主动网络安全机制

分析了主动网络安全的研究现状，遵循主动网络安全工作组提出的安全规范，提出了一各通用的主动网络安全机制。根据主动网络的特点，提出了2个重要的保护对象：主动结点和主动信包。该机制构建了认证授权和访问控制2个执行引擎，设计了证书库和安全策略库。执行引擎在为执行环境提供请求服务时，查阅证书库可对创建主动信包的主体进行身份认证，并参考安全策略对主动信包访问系统资源进行控制，从而有效地保护了主动节点。引入了权能概念，并利用权能描述了动态、复杂的安全控制策略。采用了数字签名技术和软状态存储机制来保护和隔离主动信包。该机制能够有效地保护主动节点和主动信包，基于该机制实现的安全设施可作为通用组件构建安全的主动网络。     

面向智能电网移动终端的轻量级认证方案

针对智能电网移动终端秘密存储数据容易受到攻击,提出一个基于BS-PUF的轻量级认证方案。使用随机假名实现了身份信息隐私保护,基于椭圆曲线构造有效降低智能电网节点的计算量,实现了轻量化、低时延认证。采用BS-PUF不仅可减少敏感信息存储,还可抵御侧信道攻击。动态更新机制进一步提高了口令安全性。使用BAN逻辑对协议的正确性进行了验证,基于eCK模型对协议的安全性进行了形式化分析,通过仿真实验评估了协议的性能。分析结果表明,所提出的协议可满足智能电网移动终端认证协议的安全性及性能需求,且能有效保护用户身份隐私。     

基于物联网的身份双向认证机制研究

在物联网中要保证信息来源的准确真实性,就需要严格确保网络中接入设备的合法性.提出了1种全新的身份双向认证机制,通过对传感器节点的ID身份信息和初始工作状态信息进行认证来判断该节点身份的合法性.同时在终端基站引入了传感器节点信息表定时更换机制,对传感器节点的ID信息和工作状态信息进行实时更新.在传感器节点认证过程中加入了自动告警机制,后台基站显示认证中告警类型.当身份认证失败,基站控制端发送命令启用备用传感器节点,保证了信息采集的顺利及时进行.实验结果显示,该方案能够有效提高安全性,同时缩短认证响应时间.     

基于区块链的物联网跨域隐私保护管理系统

在日益去中心化的物联网场景中，为了解决由于单节点故障、间歇性的无线连接以及设备之间缺乏信任而导致的包括身份隐私泄漏、数据安全性和完整性等问题，本文基于区块链技术提出并设计了面向物联网异构设备群的跨域隐私保护管理系统。本系统采用去中心化的区块链技术以及链外存储技术构建可信数据共享平台；为了保护设备的隐私，本系统通过跨域身份认证模块确保设备以匿名方式进行跨域身份认证；采用属性加密技术实现跨域安全通信模块，为设备提供细粒度的数据控制访问；此外，本系统还为设备部署通信中间件来提高物联网设备与区块链节点之间的通信效率。系统仿真实验结果表明本文提出的系统原型可以在确保设备不泄漏身份隐私以及保护通信数据安全性的前提下达到较高的跨域效率。     

基于身份签名的P2P语音认证及密钥协商方法

为了解决P2P语音网络中节点认证和密钥协商问题,提出了一种基于身份签名的节点双向认证及密钥协商方法.首先从可信节点群中获得签名密钥碎片,并将其组合成节点的签名密钥,然后通过通信双方安全交互来完成相互认证.结合基于身份签名的Oakley密钥协商协议实现了通信双方的会话密钥协商.提出的基于身份签名的P2P语音认证及密钥协商...     

天地一体化网络节点的移动认证协议设计

针对天地一体化网络节点的高速移动和频繁跨域问题,该文基于公钥基础设施框架设计了一套移动认证协议.该协议以公钥密码算法为基础,实现了相邻节点间的匿名认证;利用门限理论将私钥分量分配给n个节点,实现多节点协作认证和权限的动态回收;结合分布式认证与链式认证,实现了分布式的公钥基础设计,为节点高速移动提供了认证基础.该协议体系无中心、自适应、可追踪,符合天地一体化网络的无中心和节点对等等特性.实验表明,与传统的分布式认证相比,该体系具有更强的认证成功率和安全性.     

基于双线性对的分簇WSN密钥协商和认证协议

利用双线性对灵活和简便的特点,提出基于双线性对的分簇WSN密钥协商和认证协议,针对分簇无线传感器网络实现安全有效的管理。该协议基于节点身份和轮值实现节点间的双向身份认证,能保持会话密钥的新鲜,从而提高网络的安全性。仿真实验表明,该方案能够有效提高网络的安全性,且具有通信开销小的特点。     

击键特征加强口令身份认证安全性的研究

目前 ,绝大多数计算机系统的安全性都是通过口令保护机制实现的 ,但口令易被盗用 ,存在着安全隐患。为此本文提出了将传统的口令认证机制同用户输入口令时生成的击键特征相结合进行身份认证 ,以此来加强传统的口令认证方式的安全性。同时建立了 BP神经网络对此进行实验 ,并给出了实验结果。     

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