计算机专业英语.doc

New technique of the computer networkAbstractThe 21 century is an ages of the information economy, being the computer network technique of representative techniques this ages, will be at very fast speed develop soon in continuously creatively, and will go deep into the peoples work, life and study. Therefore, control this technique and then seem to be more to deliver the importance. Now I mainly introduce the new technique of a few networks in actuality live of application.keywordsInternet Digital Certificates Digital Wallets Grid Storage1. ForewordInternet turns 36, still a work in progressThirty-six years after computer scientists at UCLA linked two bulky computers using a 15-foot gray cable, testing a new way for exchanging data over networks, what would ultimately become the Internet remains a work in progress.University researchers are experimenting with ways to increase its capacity and speed. Programmers are trying to imbue Web pages with intelligence. And work is underway to re-engineer the network to reduce spam(junk mail) and security troubles.All the while threats loom: Critics warn that commercial, legal and political pressures could hinder the types of innovations that made the Internet what it is today.Stephen Crocker and Vinton Cerf were among the graduate students who joined UCLA professor Len Kleinrock in an engineering lab on Sept. 2, 1969, as bits of meaningless test data flowed silently between the two computers. By January, three other nodes joined the fledgling network.Then came e-mail a few years later, a core communications protocol called TCP/IP in the late 70s, the domain name system in the 80s and the World Wide Web - now the second most popular application behind e-mail - in 1990. The Internet expanded beyond its initial military and educational domain into businesses and homes around the world.Today, Crocker continues work on the Internet, designing better tools for collaboration. And as security chairman for the Internets key oversight body, he is trying to defend the core addressing system from outside threats.He acknowledges the Internet he helped build is far from finished, and changes are in store to meet growing demands for multimedia. Network providers now make only best efforts at delivering data packets, and Crocker said better guarantees are needed to prevent the skips and stutters now common with video.Cerf, now at MCI Inc., said he wished he could have designed the Internet with security built-in. Microsoft Corp., Yahoo Inc. and America Online Inc., among others, are currently trying to retrofit the network so e-mail senders can be authenticated - a way to cut down on junk messages sent using spoofed addresses.Many features being developed today wouldnt have been possible at birth given the slower computing speeds and narrower Internet pipes, or bandwidth, Cerf said.2.Digital CertificatesDigital certificates are data files used to establish the identity of people and electronic assets on the Internet. They allow for secure, encrypted online communication and are often used to protect online transactions.Digital certificates are issued by a trusted third party known as a certification authority (CA). The CA validates the identity of a certificate holder and “signs” the certificate to attest that it hasnt been forged or altered in any way.New Uses For Digital CertificatesDigital certificates are now being used to provide security and validation for wireless connections, and hardware manufacturers are one of the latest groups to use them. Not long ago, VeriSign Inc. announced its Cable Modem Authentication Services, which allow hardware manufacturers to embed digital certificates into cable modems to help prevent the pirating of broadband services through device cloning.Using VeriSign software, hardware makers can generate cryptographic keys and corresponding digital certificates that manufacturers or cable service providers can use to automatically identify individual modems.This ast-mileauthentication not only protects the value of existing content and services but also positions cable system operators to bring a broad new range of content, applications and value-added services to market.When a certificate is digitally signed by a CA, its owner can use it as an electronic passport to prove his identity. It can be presented to Web sites, networks or individuals that require secure access.Identifying information embedded in the certificate includes the holder s name and e-mail address, the name of the CA, a serial number and any activation or expiration data for the certificate. When a users identity is verified by the CA, the certificate uses the holders public encryption key to protect this data.Public keys are also employed by certificates that a Web server uses to confirm the authenticity of a Web site for a users browser. When a user wants to send confidential information to a Web server, such as a credit-card number for an online transaction, the browser will access the public key in the servers digital certificate to verify its identity.Role of Public-Key CryptographyThe public key is one half of a pair of keys used in public-key cryptography, which provides the foundation for digital certificates.Public-key cryptography uses matched public and private keys for encryption and decryption. These keys have a numerical value thats used by an algorithm to scramble information and make it readable only to users with the corresponding decryption key.A persons public key is used by others to encrypt information meant only for that person. When he receives the information, he uses his corresponding private key, which is kept secret, to decrypt the data. A persons public key can be distributed without damaging the private key. A Web server using a digital certificate can use its private key to make sure that only it can decrypt confidential information sent to it over the Internet.The Web servers certificate is validated by a self-signed CA certificate that identifies the issuing CA. CA certificates are preinstalled on most major Web browsers, including Microsoft Internet Explorer and Netscape Navigator.The CA certificate tells users whether they can trust the Web server certificate when its presented to the browser. If the validity of the Web server certificate is affirmed, the certificates public key is used to secure information for the server using Secure Sockets Layer (SSL) technology.Digital certificates are used by the SSL security protocol to create a secure “pipe” between two parties that seek confidential communication. SSL is used in most major Web browsers and commercial Web servers.3. Digital Wallets-A digital wallet is software that enables users to pay for goods on the Web It holds credit-card numbers and other personal information such as a shipping address Once entered，the data automatically populates order fields at merchant sites -When using a digital wallet，consumers dont need to fill out order forms on each site when they purchase an item because the information has already been stored and is automatically updated and entered into the order fields across merchant sites Consumers also benefit when using digital wallets because their information is encrypted or protected by a private software code And merchants benefit by receiving protection against fraud -Digital wallets are available to consumers free of charge，and theyre fairly easy to obtain For example，when a consumer makes a purchase at a merchant site thats set up to handle server-side digital wallets，he types his name and payment and shipping information into the merchants own form At the end of the purchase，one consumer is asked to sign up for a wallet of his choice by entering a user name and password for future purchases Users can also acquire wallets at a wallet vendors site -Although a wallet is free for consumers，vendors charge merchants for wallets -Digital wallets come in two main types:client-side and server- side Within those divisions are wallets that work only on specific merchant sites and those that are merchant agnostic -Client-based digital wallets，the older of the two types，are falling by the wayside，according to analysts，because they require users to download and install software A user downloads the wallet application and inputs payment and mailing information At that point，the information is secured and encrypted on the users hard drive The user retains control of his credit card and personal information locally -With a server-based wallet，a user fills out his personal information，and a cookie is automatically downloaded （A cookie is a text file that contains information about the user ）In this scenario，the consumer information resides on the server of a financial institution or a digital wallet vendor rather than on the users PC -Server-side wallets provide assurance against merchant fraud because they use certificates to verify the identity of all parties When a party makes a transaction，it presents its certificate to the other parties involved A certificate is an attachment to an electronic message used to verify the identity of the party and to provide the receiver with the means to encode a reply -Furthermore，the cardholders sensitive data is typically housed at a financial institution，so theres an extra sense of security because financial environments generally provide the highest degree of security -But even though wallets provide easy shopping online， adoption hasnt been widespread -Standards are pivotal to the success of digital wallets -Last month，major vendors，including Microsoft Corp ， Sun Microsystems Inc and America Online Inc announced their endorsement of a new standard called EMCL，or E-Commerce Modeling Language，to give Web merchants a standardized way to collect electronic data for shipping，billing and payment 4. Grid StorageDefinition: Grid storage, analogous to grid computing, is a new model for deploying and managing storage distributed across multiple systems and networks, making efficient use of available storage capacity without requiring a large, centralized switching system.A grid is, in fact, a meshed network in which no single centralized switch or hub controls routing. Grids offer almost unlimited scalability in size and performance because they arent constrained by the need for ever-larger central switches. Grid networks thus reduce component costs and produce a reliable and resilient structure.Applying the grid concept to a computer network lets us harness available but unused resources by dynamically allocating and deallocating capacity, bandwidth and processing among numerous distributed computers. A computing grid can span locations, organizations, machine architectures and software boundaries, offering power, collaboration and information access to connected users. Universities and research facilities are using grids to build what amounts to supercomputer capability from PCs, Macintoshes and Linux boxes.After grid computing came into being, it was only a matter of time before a similar model would emerge for making use of distributed data storage. Most storage networks are built in star configurations, where all servers and storage devices are connected to a single central switch. In contrast, grid topology is built with a network of interconnected smaller switches that can scale as bandwidth increases and continue to deliver improved reliability and higher performance and connectivity.What Is Grid Storage?Based on current and proposed products, it appears that a grid storage system should include the following:Modular storage arrays: These systems are connected across a storage network using serial ATA disks. The systems can be block-oriented storage arrays or network-attached storage gateways and servers.Common virtualization layer: Storage must be organized as a single logical pool of resources available to users.Data redundancy and availability: Multiple copies of data should exist across nodes in the grid, creating redundant data access and availability in case of a component failure.Common management: A single level of management across all nodes should cover the areas of data security, mobility and migration, capacity on demand, and provisioning.Simplified platform/management architecture: Because common management is so important, the tasks involved in administration should be organized in modular fashion, allowing the autodiscovery of new nodes in the grid and automating volume and file management.Three Basic BenefitsApplying grid topology to a storage network provides several benefits, including the following:Reliability. A well-designed grid network is extremely resilient. Rather than providing just two paths between any two nodes, the grid offers multiple paths between each storage node. This makes it easy to service and replace components in case of failure, with minimal impact on system availability or downtime.Performance. The same factors that lead to reliability also can improve performance. Not requiring a centralized switch with many ports eliminates a potential performance bottleneck, and applying load-balancing techniques to the multiple paths available offers consistent performance for the entire network.Scalability. Its easy to expand a grid network using inexpensive switches with low port counts to accommodate additional servers for increased performance, bandwidth and capacity. In essence, grid storage is a way to scale out rather than up, using relatively inexpensive storage building blocks.新技术的计算机网络摘要21世纪是信息经济的时代，是具有代表性的技术，计算机网络技术这个年龄段，将在非常快的速度在不断创造性地发展很快，并进入人们的工作，生活和学习深。因此，控制这种技术，然后似乎更交付的重要性。现在我主要介绍了一些在现实网络的新技术的应用现场。关键词互联网数字钱包网格存储数字证书1。前言互联网变成36，仍然是一个进展中的工作三十六年后，在加州大学洛杉矶分校的计算机科学家使用一个连接两个15英尺的灰色电缆笨重的计算机，通过网络测试，你会最终成为互联网交换数据的一种新的方式仍然是一个正在进行的工作。大学的研究人员正在试验的方法，以增加其容量和速度。编程人员正在设法注入更多的智能网页。的工作也正在进行重新设计网络以减少垃圾邮件（垃圾邮件）和安全麻烦。而所有的威胁织机：批评人士警告说，商业，法律和政治压力可能会阻碍创新，使得互联网有今天的类型。斯蒂芬克罗克和Vinton Cerf在谁的研究生参加了一个工程实验室在1969年9月2日加州大学洛杉矶分校教授Len Kleinrock，因为毫无意义的试验数据位流静静地在两台计算机之间。2010年1月其他三个“节点”加入了这个网络。然后是电子邮件，几年后，一个核心通信协议呼吁在70年代末的TCP / IP协议，在80年代的域名系统和万维网 - 1990年 - 现在最流行的背后第二电子邮件应用。互联网扩大超出其最初的军事和教育领域为企业和家庭在世界各地。如今，克罗克在互联网上继续工作，设计的协作更好的工具。随着互联网安全的主要监督机构的主席，他正试图捍卫的核心系统应对来自外部的威胁。他承认，他帮助建立的互联网还远远没有完成，店里的变化，以满足多媒体日益增长的需求。现在以网络供应商提供数据包只在“最佳努力”，和克罗克说，更好的保障需要，防止跳过和口吃现在视频常见。瑟夫目前在MCI公司说，他希望他能够在互联网与安全性设计内置。微