【導(dǎo)讀】逐漸成為計算機(jī)安全的主流。手段，避免非法活動的相關(guān)信息的安全性。因此保持完整性是信息安全的基本要求?？煽啃孕畔⒌恼鎸嵭灾饕谴_認(rèn)信息所有者和發(fā)件人的身份。可靠性表明該系統(tǒng)能夠在規(guī)定的時間和條件下完成相關(guān)的功能。計算機(jī)網(wǎng)絡(luò)所面臨的各種威脅有：惡意攻擊，泄漏軟件，計算機(jī)病毒和自然災(zāi)害。欺騙、病毒和邏輯炸彈。在1996年，計算機(jī)病毒已經(jīng)造成美國制造業(yè)大1億美元的經(jīng)濟(jì)損失?；ヂ?lián)網(wǎng)提供了計算機(jī)病毒容易擴(kuò)散的環(huán)境，同時增加了消滅他們的困難。計算機(jī)病毒已經(jīng)嚴(yán)重威脅到網(wǎng)絡(luò)安全，特別是專。算機(jī)病毒能夠在短時間內(nèi)通過網(wǎng)絡(luò)廣泛傳播。在潛伏期內(nèi)，它并不表現(xiàn)出任何擾亂行動，因此很難發(fā)現(xiàn)病毒。一旦病毒發(fā)作，它能造成嚴(yán)重破壞。按寄生，計算機(jī)病毒可分成引導(dǎo)病毒、文件病毒和混合病毒。它是一種常見病毒，利用計算機(jī)系統(tǒng)通常不檢查引導(dǎo)部。按寄生在磁盤的位置，它能進(jìn)一步分成主引導(dǎo)記錄病毒和段引導(dǎo)記錄病毒。

　　

【正文】 nages difficulty by transmitting information with secure ways. The advantage of public cipher code can be made to apply to work openended requirements, and to fulfill digital signature and verification. However, algorithm is plex that will make a slow speed in data encryption. With the development of modem electronic technique and encryption technology, public cipher code algorithm will gradually bee the mainstream in work security encryption system. People 15 usually bine regular cipher and public one together in work security application. Regular work data encryption has link, node and endtoend ways. As the most mon used way of encryption, link encryption can be achieved between link layer and physical layer in work with hardware. It is used to protect data transmitted in munication node, transparency for users. Node encryption improves link encryption and get over defects that link encryption will be easily illegal access. It also can encrypt in protocol transport layer, and make encryption protect on data transmitted between original node and aim node. Endtoend encryption is for work layer, which encrypts high level subject in work and data transmitted in presentation layer, not for information in low level protocol. It is often finished by software, at a lower cost and higher security than link encryption. Access control technology It is the main technology for work security precaution and protection. And the ke y mission is to make sure that work resources will not be illegal used and access. This technology regulates manipulation authority by users of every files and resources, such as readable, recordable and revisable. It is expected that all of the information resources could be collectively managed, without ambiguous and confliction between ever regulations. It should be with auditing function to record all activities for further check as well as providing granule control. To be an important measure to safeguard security of work system and protect work resources, access control technology is one of the most important core ones for guaranteeing work security. technology At present, the increasingly developed work technology has supplied various ways of transmission, so virus immensely threats work security with diversified route of transmission. Specialized antivirus software can be considered to be the most monly way of banishing puter virus, which can also automatically detect and delete virus in EMS memory, BIOS and disks. However, the exploration and renovation of antivirus software is always far behind the appearance of branchnew virus, so it sometimes can not detect or delete some virus. Although, edition has been increasingly updated and functions improvingly widened, program with virus and regular program have same similarity and target specificity. Above all, people can hardly predict how the virus develop and change in the future, so we also have huge difficulty in 16 exploring software or hardware instruments that banish all virus with foresight function. Furthermore, once virus successfully get through system and perate or offend authorized attack, attacker usually implant cockhorse or logic bomb in system for further attacking system and providing convenient conditions. Inter challenges a lot antivirus software. Nowandays, dozens of new virus appear everyday, and most of them transmitted through inter. In order to efficiently protect information of enterprises, antivirus software is supposed to support all Inter protocol and mail system that may be used by all enterprises, lastly to apply to and keep the pace with the changing world. Some antivirus software like Norton, McAfee mande a great progress. Only effectively cut of the access for virus, can enterprises and uses be protected to avoid breakout of virus and cause economic damages. : With the rapid development of puter technology, puter has been a tool while work to be one of the important ponents in our daily work, study and lives. As a result, work security technology has bee the key point in information work development. When people step into information society, it has turned into significant strategy of social development. Network security technology is the irreplaceable guarantee to force the social development. China still exists in the original stage on research and product exploration of information work technology, which means we should research, develop and explore largely to safeguard information work security, thus improving fast development of national economy. 17 18 指導(dǎo)教師評語： 簽名： 年 月 日