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1、UNIT 9 Computer Security and Virus,计算机专业英语,COMPETENCIES,After you have read this unit, you should be able to: Describe computer security. Describe some security techniques. Describe the differences of virus, worm and Trojan Horse. Know how to protect your computers.,Text A,Compute Security,Concept C
2、heck,Explain the differences between hackers and crackers? What is computer security? Describe some security techniques.,New Words and Phrases,unauthorized access 非授权访问 malicious adj. 恶意的 confidentiality n. 机密性 integrity n. 完整性 availability n. 有效性 cryptographic adj. 用密码写的 vulnerability n. 脆弱点,New Wo
3、rds and Phrases,encryption n. 加密 plaintext n. 明文 ciphertext n. 密文 algorithm n. 算法 public key 公钥 private key 私钥,New Words and Phrases,access control 访问控制 discretionary access control 自由访问控制 mandatory access control 强制访问控制 network security 网络安全 virtual private network 虚拟私用网 security perimeter 安全边界 sub
4、network n. 子网,New Words and Phrases,firewall n. 防火墙 client n. 客户机 sever n. 服务器 router n. 路由器 hub n. 集线器 intrusion detection 入侵检测 anomaly detection 异常检测 misuse detection 误用检测,Notes,1 Life is full of tradeoffs and computer security is no different. 分析 tradeoff 是指权衡、折衷。 这句话的意思是：生活充满了权衡，计算机安全也不例外。 2 Som
5、e people think of these two groups as being the same . 分析 think of as 是一个词组，是“把看作”的意思。,Notes,3 Encryption is a very effective technique for preserving the secrecy of computer data, and in some cases it can also be employed to ensure integrity and availability. 分析 it 指的是encryption，be employed to 在这里可
6、以理解为be used to。 4 Computer security implies that access be limited to authorized users. 分析 imply that be 引导的从句要用动词原形。,Notes,5 The matrix specifies for each subject the objects that can be accessed and the kinds of access that are allowed. 分析这句话是双宾语结构，其中each subject为直接宾语，the objects和the kinds of acce
7、ss为间接宾语。 6 Programs, however, are subject to error, which can affect computer security. 分析 be subject to 受的影响。,Notes,7 Integrity is a much more encompassing issue for databases than for general applications programs. 分析 morethan相对一般的应用程序而言，完整性对于数据库来说是一个更重要的问题。 8 Database systems are especially prone
8、 to inference and aggregation. 分析 be prone to 易于，有的倾向。这句话的意思是：数据库系统更易于推理和聚合。,Notes,9 A security perimeter is a logical boundary surrounding all resources that are controlled and protected. 分析 that 引导的定语从句，对resources进行修饰。,Text B,Virus,Concept Check,Describe the differences of virus, worm and Trojan H
9、orse. How to protect your computers? What is virus? Describe some characters of virus.,New Words and Phrases,virus n. 病毒 replicate v. 复制 halt n. 停止 antivirus v. 抗病毒 worm n. 蠕虫 Trojan Horse 特洛伊木马 executable file 可执行文件 trickery n. 欺骗,New Words and Phrases,mythological adj. 虚构的 activate vt. 激活 backdoor
10、 n. 后门 up-to-date 最近的 spamming n. 垃圾邮件 folder n. 文件夹,New Words and Phrases,icon n. 图标 executable adj. 可执行的 attachment n. 附件 fake vt. 伪装 domain name 域名 boot v. 启动，引导,Notes,1 Virus is a program or a piece of code that is loaded onto your computer without your knowledge and runs against your wishes. 分析
11、这是个定语从句，由and 连接两个部分，即that is and 2 ARPANET 分析 ARPANET指的是ARPA 计算机网 （美国国防部高级研究计划局建立的计算机网。这个国际网允许其成员使用其设备并对大批不同的计算机存取数据）。,Notes,3 People continue the spread of a computer virus, mostly unknowingly, by sharing infecting files or sending e-mails with viruses as attachments in the e-mail. 分析 mostly unknow
12、ingly是插入语，指大多数情况下，不知不觉地。 4 One example would be for a worm to send a copy of itself to everyone listed in your e-mail address book. 分析 listed in your e-mail address book, 过去分词短语作定语，修饰everyone。,Notes,5 Due to the copying nature of a worm and its capability to travel across networks the end result in
13、most cases is that the worm consumes too much system memory (or network bandwidth), causing Web servers, network servers and individual computers to stop responding. 分析这句话的主体部分为：the end result is that。前面的句子表原因。,Notes,6 Small.H, originally named lsass.exe, spreads itself using an internal spamming-en
14、gine that is controlled through a previously set-up backdoor. 分析 originally named lsass.exe, 是插入语，指Small.H，原来叫做lsass.exe。 7 A new variant of Netsky worm - Netsky.D was found on March 1st, 2004 and is spreading fast in the wild. 分析 a new variant of，指的是某种类型病毒的变种。,Notes,8Computers infected by the worm
15、send e-mail messages with a URL that points to the worms file. 分析这句话的主体部分是Computers send ，infected by the worm是对computers的修饰，指被蠕虫感染的计算机。 9 The worm fakes (obfuscates) the download URL and inserts the users domain name and e-mail address to the message body to make the message look trustworthy. 分析这句话中，第一个to是和inserts相匹配，第二个to表目的。,Key Terms,security n. 安全性 portability n. 可移植性 alarm system 报警系统 interception n. 截取，窃听 packet filtering 包过滤 bastion host 保垒主机 proxy gateway 代理网关 boot sector viruses 引导扇区病毒 macro viruses 宏病毒 rescue disk 应急磁盘,Reading Materials Firewall and Firewall Software,Answer the
