8000-word computer graduation thesis 1
On Computer Network Security and Virus Protection
1 Factors affecting computer network security
The main source of computer network security problems is the inevitable systematicness and fragility of the network itself.
The following are the specific factors that affect computer network security.
1. 1 unauthorized access.
Unauthorized access refers to the unauthorized use of network resources without the consent of the original user.
People often use false identities or illegal attacks to avoid accessing authentication systems, forcibly entering network systems, illegally using network resources, and even maliciously stealing or modifying some information.
Illegal use of 1.2 information.
The illegal use of information mainly includes the following forms: first, destroying information; The second is the leakage of information; The third is the transmission of illegal information flow.
Among them, the destruction information refers to that the network intruder intercepts the resource package being uploaded or downloaded in the network, and processes or modifies it to make the resource package useless, or adds some information beneficial to himself, and returns the resource package after adding the information.
Information leakage means that passive network intruders eavesdrop on some information through electromagnetic leakage or self-wiring [1], or screen or infer useful information by analyzing relevant data of information. In this process, it will not cause any damage to the information, but the information loses its confidentiality.
The transmission of illegal information flow means that users are allowing themselves to communicate with other users, but other types of communication will be prohibited.
1.3 Wrong or illegal use of network resources.
Users do not set reasonable access rights or control access to resources, which leads to accidental loss or damage of resources and even the invasion of some harmful information.
Or illegal users forcibly log in, using network resources causes resource consumption and damages the interests of the original users.
1.4 Influence of environment on network security.
The influence of environment on network security can be divided into the influence of natural environment on network security and the influence of social environment on network security.
For example, under the influence of bad weather, cables are damaged, resulting in network system paralysis and even computer damage.
Then, when people do the operation of generating electromagnetic radiation, the radiation will destroy the data transmitted by the network, which may be recorded by bad molecules, leading to information leakage.
1.5 software vulnerabilities.
There are different softwares installed in the computer, and some softwares are flawed in design, which will damage the user's computer.
Common software vulnerabilities mainly exist in the following parts: First, the operating system; Second, TCP/IP protocol; Third, password setting; Fourth, the database.
The existence of vulnerabilities will give hackers a chance to attack, and once the virus invades, it will have serious consequences.
1.6 denial of service attack.
Denial of service attacks will cause strong interference to the network service system, hinder the normal operation of the network service system, slow down the operation of programs, and gradually paralyze the network of the whole system, resulting in legal users not being able to use it normally, and even legal users cannot enter the computer network for related operations and obtain corresponding services.
2 the concept and characteristics of network virus
Network virus refers to a set of instruction integration program codes compiled by some people using the inherent vulnerability of computer software and hardware.
Network viruses invade computers in four ways: one is code replacement; Second, source code embedding; Third, additional shell; Fourth, modify the system [2].
Although viruses invade in different ways, they will all cause damage to computers.
Generally speaking, viruses have the following characteristics:
2. 1 Network virus has strong camouflage and reproductive attraction.
With the maturity of computer technology, the harm of network virus is becoming more and more serious. It can not only tamper with computer programs, but also cause some damage or changes to data and information, thus posing a serious threat to the safety of computer users.
Although some antivirus software will be installed on users' computers, network viruses have strong camouflage and concealment, and are generally difficult to be found. Therefore, even if users use antivirus software to kill viruses, they cannot be removed, which will cause damage to users' information and other documents.
In addition, computer viruses have strong reproductive ability, and network viruses can infect each other. In the process of virus expansion, it will cause certain infection to the whole user group. Once the virus mutates, it will be very destructive and aggressive.
2.2 Network viruses have a certain incubation period and have a strong attack power.
After a computer is invaded by a virus, there is usually a certain incubation period. In a certain period of time, the virus will break out in an all-round way, posing a serious threat to the network security of computer users.
Network viruses also have a strong attack power, mainly stealing users' information, and then revealing some important information or files that need to be kept secret.
Network viruses pose a serious threat to the security of computer users, so we should pay attention to the protection of computer viruses, and the most important thing is to protect the security of computer users' data.
3 Effective measures for computer network security and virus protection
3. 1 prevention and protection software.
Under normal circumstances, we will install anti-virus software in the computer, and sometimes even anti-black software. The purpose of installing these softwares is to prevent viruses from invading the computer.
Furthermore, you must be vigilant when using U disk or CD-ROM, and never use those disks or game disks with unknown sources. If we must use these disks, we should do a good job of antivirus and cleaning up.
Also, don't download software from some unreliable websites, because these softwares are likely to carry viruses, which will cause serious damage to your computer after installation.
Also, don't open or browse emails or web pages of unknown origin at will, because these emails or web pages are likely to contain malicious code.
Finally, it is necessary to form regular backups or updates of important files.
3.2 Establishment of security module.
We can use the network access function module as the first control protection layer [3]. Specifically, the function module should restrict the users who use the network, limit the use time of users and establish a blacklist to record illegal users.
At the same time, through the establishment of an intelligent network log system, the function of the system is to automatically record the user's progress or usage. With the establishment of this system, we can find out whether there is a virus invading the computer.
3.3 Ensure the safety of transmission lines.
In order to ensure the safety of transmission lines, we can protect them by burying them underground or taking other protective measures.
This not only ensures the safety of transmission lines, but also keeps them away from radiation, so as to reduce the problem of data loss or information error caused by electromagnetic interference.
Also, put the line concentrator in a position that can be monitored to prevent the line from being connected externally.
Then there is the need to check the connected ports to prevent eavesdropping.
3.4 Network encryption.
We protect important data specially, for example, by setting encryption algorithm or key as protection.
When setting a password, it is necessary to ensure that the difficulty of the password cannot be related to the user's personal information. The ways of network encryption include link encryption, end-to-end encryption and node encryption.
3.5 Access control.
On the basis of authenticating users, control users' rights.
Authentication refers to the removal of relevant restrictions on user services to support access control after users pass authentication.
You can restrict the storage matrix in different ways, such as setting important files as read-only, write-only or modifiable, which is the restriction on the storage matrix.
3.6 Adopt the identification mechanism.
Authentication is mainly to identify the identity of users by identifying messages or digital signatures, and to grant users rights so that users can obtain corresponding services.
After the certification of both parties, the dangerous components were eliminated and the identity tests of both parties were successfully carried out.
4 conclusion
Computers bring you a lot of convenience, but also bring you a lot of risks, so it is very necessary and important to pay attention to computer network security and prevent network viruses.
Computer graduation thesis 8000 words 2
Discussion on computer network security vulnerabilities and solutions
First, the main security loopholes in computer networks at present
(1) computer network software.
In the normal operation of computer network, computer software is one of the most important components. Generally, it needs to be downloaded through the network before it can be used, so as to truly meet the relevant operating requirements.
But in the process of downloading, some viruses may also enter the computer together, threatening the security of the computer network.
(2) Computer hardware.
For the operation of computer network, computer hardware is a very important basic component. If it has security problems, it will have a great impact on the normal use of computer networks.
At present, some security vulnerabilities in computer hardware are improperly used, which seriously affects the normal communication of computer hardware facilities.
Generally speaking, this situation of computer network is mainly attacked by hackers, which leads to a large number of stolen property information and personal information of users, which has a serious impact on the safe operation of computer network.