基于Diffie-Hellman密钥交换的Web安全传输

采用SSL(Secure Sockets Layer)安全传输协议实现Web方式下的安全传输需要对整个传输通道的数据都进行加密处理,因此其运算速度较慢,对Web服务器的性能有很大影响.为此提出了一种利用DH(Diffie Hellman)密钥交换所需的参数并利用DES(Data Enerypfion Standard)分组密钥算法进行加密的安全传输过程.该方法以明文方式传送DH密钥交换的参数,客户端和服务器端利用这些参数计算共知的密钥,并用该密钥对希望加密的数据进行DES加密.不但实现了Web方式下数据的安全传输,而且因DH和DES算法有较快的速度以及只对希望加密的数据信息进行加密,所以对Web服务器的性能影响比采用SSL下降了70%以上.该方法已经在"JL金融保卫MIS(Management Information System)系统"中得到较好的应用效果.     

浅谈加密服务器上的密钥管理

信息安全问题是关系国家安全和社会稳定的重大问题。加密服务器就是针对这一问题的一个解决方案。本文主要介绍加密服务器密钥存储区中密钥的管理。     

一种基于SOCKS 5的Web安全代理技术

综合公钥密码算法(RSA)和数据加密标准(DES)的优势,用DES方法加密待传送的Web数据,使用RSA方法对DES密钥进行加密,提出一种基于SOCKS 5的,RSA和DES相结合的Web安全代理方案.通过性能测试和安全性分析表明,使用RSA传递DES密钥可保证DES每次加密都使用新的密钥,杜绝黑客通过分析明文/密文获得密钥,从而能防御网络数据包被恶意截取后造成泄密,安全代理既保证Web数据的加密速度,又保证DES密钥的安全性和可管理性.     

基于SQL Server 2008安全数据库服务器的构建

研究数据库服务器的安全措施.以SQL Server 2008为例,重点介绍了SQL Server 2008的安全特性,详细阐述了基于SQL Server 2008如何构建安全的数据库服务器,具体包括安全配置管理、验证管理、授权管理、加密和密钥管理、审查管理.     

静态Web服务器的设计与实现

静态Web服务器是专门用于提供静态网站访问服务的Web服务器,与动态Web服务器相比,能够为静态网站提供更高的访问效率和安全性,还能够让静态网站的内容更多地被搜索引擎收录以提高网站的广告收入 本文从实际应用需求出发,设计一个安全、高效、易用的静态Web服务器来提高网站运营效率和效益.本设计通过提高服务器安全验证来保障服务器安全,设置资源池来提高服务器性能,提供最简单灵活的配置功能来增加服务器的易用性.     

基于转发隔离的文件安全传输系统

针对文件传输存在的安全性问题,设计与实现了基于转发隔离的文件安全传输系统。首先,采用转发隔离技术,对客户端和文件接收服务器进行隔离,保证文件接收服务器的安全。再者,利用密钥服务器来生成、颁发、管理文件加密、解密时所需的密钥,保证密钥存储和传输的安全。最后,利用改进的数字信封来实现文件完整性的验证,提高文件传输的速度和效率。实验结果表明基于转发隔离的文件传输系统在保证文件安全传输的同时,提高了系统整体的性能。     

网站安全技术与防火墙的应用

介绍了网站(Web)常见的安全漏洞，以及如何提高网站服务器的安全性和稳定性，同时介绍了防火墙(firewall)技术在网站安全中的应用等方面的问题，     

OpenSSL初步探究

众所周知，在网络通信方面，除了HTTP协议，还有一种就是HTTPS。它是一种安全的HTTP协议，通常使用了443端口。要实现Web服务器的安全通信认证，一般可以借助证书颁发机构或者自己搭建一个证书服务器来实现。本篇文章将给大家介绍一下在WindowsXPProfessional系统上借助OpenSSL来实现Web网站安全通信，即HTTPS。     

数据挖掘技术在Web网站安全中的应用

Web网站的安全是影响商务网站发展的一个十分重要的问题。介绍了数据挖掘技术及其在Web网站安全中的应用。从三个层次讨论Web网站的安全:基于数据挖掘技术的网络入侵检测,实现网站低层网络级安全;在系统用户级实现异常检测,防止系统用户的越权行为;对Web日志进行数据挖掘,发现Web用户的异常行为,实现高层安全。     

密文数据库中支持快速密钥更新的数据共享方案

云环境中常采用属性基加密机制进行一对多的数据共享,这种方式会影响到系统效率,数据拥有者在更新加密密钥时操作复杂。针对此问题,提出一种支持快速密钥更新的数据分享方案。数据拥有者使用属性基加密数据密钥并传送给数据中心,重加密机制支持密钥的快速更新,降低了用户和服务器的工作量,并提高系统安全性。方案基于判定双线性Diffie-Hellman(Decision bilinear Diffie-Hellman,DBDH)假设,在标准模型下满足自适应选择明文攻击安全。通过与其他方案对比,该方案中属性密钥长度、密文长度有所优化,数据分享和读取数据计算开销有所减少,适用于移动终端云环境数据分享的性能需求。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-