有关于计算机的英语短文章

计算机英语一 Internet technical specifications often need to define a format syntax and are free to employ whatever notation their authors deem useful. Over the years, a modified version of BNF, called ABNF, has been popular among many Internet specifications. It balances compactness and simplicity with reasonable representational power. 互联网技术规范经常需要定义一种格式化语法并能自由地使用作者认为 是有用的任何符号。多年来，巴克斯范式(BNF)BNF)的一个修订版，即扩展巴克 斯范式(BNF)ABNF)，已经在许多互联网规范中流行。该版本平衡了压缩性和简单 性，具有合理的表达能力。 计算机英语二 X.509 describes two levels of Authentication, simple authentication, based on use of a password to verify user identity, and strong authentication, using credentials created by cryptographic methods. The standard recommends that only strong authentication should be used as the basis of providing secure services. Public-Key Cryptography is used for strong authentication, but X.509 is not dependent on the use of a particular cryptographic Algorithm, though two users wishing to authenticate must support the same Algorithm. X.509 描述了两个级别的认证，简单认证和强认证，简单认证基于使用 一个密码验证用户身份，强认证使用加密方法创建的数字证书。标准建议只 有强认证能够作为提供安全服务的基础。强认证使用公钥加密方式，但是 X.509 并不依赖于使用特殊加密算法，尽管两个用户希望认证必须支持同一 算法。 计算机英语三 X.500 is an open, distributed, online directory service which is intended to be global in scope. X.500 is a support service for data exchange which includes providing directory support for data communication services specified by other OSI application standards. The X.500 series of standards covers services available to users, the functional model and protocols connecting the component parts of the directory, an information framework and a schema of the information held by the directory, and a mechanism for allowing OSI components to authenticate each other. X.500 是一个开放的、分布式的、趋向于全球化的在线目录服务。 X.500 支持数据交换服务，该服务符合 OSI 模型和其他应用协议下的数据传送的目 录服务。X.500 这一系列标准涵盖了可用的用户服务、连接各组成部分的功 能和协议模型、目录的消息框架和信息保持、OSI 模型中各组成部分彼此授 权的支持等多个方面。