Network security and preventive measures

Network security and preventive measures 1

Abstract: With the rapid development of computer network technology, network security has increasingly become the focus of attention.

More and more computer users can access the rich information resources of the global network system without leaving home, and economic, cultural, military and social activities also strongly rely on the network. A networked society has appeared in front of us.

With the increasing number of network applications, network security issues are becoming more and more prominent.

Due to the diversity of computer network connection forms, the uneven distribution of terminals, the openness of the network and the * * * enjoyment of network resources, computer networks are vulnerable to improper behaviors such as viruses, hackers and malicious software.

In order to ensure the security and smoothness of information, it is urgent to study the security and preventive measures of the network.

This paper analyzes the main factors affecting the network security and the main attack methods, and puts forward some targeted countermeasures to strengthen the computer network security from two aspects of management and technology.

Keywords: network security; Prevention; Hidden danger; measure

introduce

With the rapid development of computer technology and the new moon of computer network, the network has penetrated into every corner of our lives.

Computer network is playing an increasingly important role.

However, while we communicate with friends, peers and get information through the Internet every day, how much do we know about this network and whether we can realize the hidden unsafe factors that the network brings us fast and convenient life and work.

1 the concept of computer network security

The specific definition of computer network security will change with the change of users. Different users have different understanding and requirements for network security.

For example, from the perspective of ordinary users, they may just want personal privacy or confidential information to be protected when transmitting on the network to avoid eavesdropping, tampering and forgery; In addition to the security of these network information, network providers should also consider how to deal with the destruction of network hardware caused by sudden natural disasters and military strikes, and how to restore network communication when the network is abnormal and maintain the continuity of network communication.

Network security essentially includes the hardware and software that constitute the network system, and the security of information transmitted on the network, so that it will not be destroyed by accidental or malicious attacks. Network security has both technical problems and management problems, which complement each other and are indispensable.

Man-made network intrusion and attack make network security face new challenges.

2. Hidden dangers and attack forms of computer network security.

2. 1 Computer network hardware security risks

Computer network hardware facilities are an indispensable part of the Internet, and the hardware facilities themselves have security risks.

The leakage of electronic radiation is the main security problem, that is to say, the electromagnetic information contained in computers and networks is leaked, which increases the danger of stealing, losing and leaking secrets; In addition, security risks are also reflected in the vulnerability of the communication part. There are four main lines for data information exchange and communication activities, namely, optical cable, telephone line, special line and microwave, and the information on the other three lines except optical cable is easy to be stolen; In addition to the above aspects, the fragility of computer operating system and hardware also lays a hidden danger for the abuse of the system.

? In addition, the removable storage medium.

Mobile storage media such as USB flash drive and mobile hard disk are widely used because of their convenience, small size, large storage capacity and portability, especially in secret-related units, which brings great hidden dangers to the information security of network systems.

2.2 computer software vulnerabilities

Hackers attack some websites and upload malicious codes to the servers of the attacked websites through carefully constructed malicious codes.

When users visit the attacked website, it may lead to the disclosure of users' private information.

No matter how powerful the software is, there will inevitably be defects or loopholes at the beginning of design, and the operating system software is no exception.

Different operating systems between system hosts are relatively independent, and vulnerabilities of the same nature will have different manifestations due to different design and development processes of operating system software.

Attackers can "conveniently" destroy computer systems through vulnerabilities, resulting in host paralysis and loss of important data, which seriously affects the normal operation of the system.

2.3 Hacker attacks and computer virus attacks

This is one of the most serious network security threats.

Attackers look for system vulnerabilities or system vulnerabilities in various ways. Because the weaknesses of the homogeneous redundant environment of network systems are the same, the probability of multiple systems failing at the same time is small, but the possibility of being breached is great. Attacking the system by intercepting and stealing, destroying the important data of the system, even paralyzing the system, poses a serious threat to network security.

The attack and spread of network viruses are extremely fast, and many computer users fail to install anti-virus software or update the virus database of anti-virus software in time for various reasons, which leads to the proliferation of network viruses. The virus program is very light, which reduces the efficiency of the system. In the worst case, it leads to system crash and data loss, causing irreparable losses, which not only seriously endangers the computer security of users, but also greatly consumes network resources, causing network congestion and bringing great inconvenience to every user.

2.4 the network's own security flaws

The network is an open environment, and TCP/IP is a general protocol, that is, IP address is used as the unique identifier of network nodes, multi-user authentication and authorization are carried out based on IP address, and the authenticity and security of data are judged according to the source IP address in IP packets. However, the biggest disadvantage of this protocol is the lack of IP address protection and authentication mechanism for the authenticity of the source IP address, which is the root of the insecurity of TCP/IP protocol.

Common attacks through TCP/IP protocol defects include: source address spoofing, IP spoofing, source routing spoofing, routing information protocol attack, SYN attack, etc.

3. Precautionary measures for network security

3. 1 firewall technology

Firewall is the barrier of network security, and configuring firewall is one of the most basic, economical and effective security measures to realize network security.

Firewall refers to the combination of software or hardware equipment, which is located between the computer of an enterprise or network group and the external channel, restricting the access of external users to the internal network and managing the access rights of internal users to the external network.

When a network is connected to the Internet, the security of the system should not only consider the computer virus and the robustness of the system, but also prevent the invasion of illegal users. At present, the prevention measures are mainly completed by firewall technology.

3.2 Data encryption technology

Data encryption technology is a technical means to re-encode information, thus hiding the content of information and making it impossible for illegal users to obtain the real content of information.

Data encryption technology is one of the main means to improve the security and confidentiality of information systems and data and prevent confidential data from being cracked by the outside world.

Data encryption technology can be divided into data storage, data transmission, data integrity identification and key management technology according to different functions.

Data storage encryption technology aims to prevent data loss in storage links, which can be divided into ciphertext storage and access, while data transmission encryption technology aims to encrypt the data stream in transmission.

Data integrity authentication is to verify the identity of people who participate in information transmission, access and related data content to meet the requirements of confidentiality. The system verifies whether the input eigenvalues meet the preset parameters by comparison, so as to realize data security protection.

3.3 anti-virus technology

With the continuous development of computer technology, computer viruses have become more and more complex and advanced, posing a great threat to computer information systems.

Antivirus software widely used for virus prevention can be divided into two categories: network antivirus software and stand-alone antivirus software.

Single-machine antivirus software is generally installed on a single PC, that is, it analyzes and scans remote resources connected to local workstations, and detects and removes viruses.

Network antivirus software is mainly based on network antivirus. Once a virus invades the network or spreads to other resources from the network, the network antivirus software will immediately detect and delete it.

Viruses spread and destroy the network mainly through data destruction and deletion, backdoor attack, denial of service, spam spread and other ways, resulting in line congestion and data loss and damage.

Then establishing a unified overall network virus prevention system is an effective solution to comprehensively protect computer networks.

3.4 server access control strategy

For the network infrastructure equipment such as servers and routers, the effective way to avoid illegal intrusion is to get rid of unnecessary network access and establish access control around the required network access.

In addition, the necessary permissions are set for users and accounts.

One is to limit the number of database administrator users and grant users the minimum permissions they need.

The second method is to cancel the permissions that the default account does not need, and choose the appropriate account to connect to the database.

3.5 Establish a more secure e-mail system

At present, some excellent e-mail security systems have high accuracy and low false alarm rate, and the unique policy module can help users manage and maintain e-mail systems easily. The accuracy of some email systems in identifying spam is close to 100%.

Users should analyze and compare in many aspects, and choose an excellent email security system to ensure the security of the network email system, so as to change the current situation of spam, email virus, email leakage and other security risks in the email system.

3.6 Improve the quality of network personnel and strengthen the responsibility of network security.

In order to strengthen the responsibility of network security, there is another important task-improving the management quality of network staff.

It is necessary to combine the data, software, hardware and other aspects of the network system to carry out safety education for staff, improve their sense of responsibility, and improve their operational skills through relevant business and technical training. Attention should be paid to the safety management of network system to avoid man-made accidents.

Due to the late start of network research in China, network security technology needs to be improved and developed.

In addition, in order to ensure the safe operation of the network, we should also formulate perfect management measures, establish strict management systems, improve laws and regulations, improve people's understanding of network security, and increase legal sanctions against computer crimes.

4. Concluding remarks

The security of computer network has been paid more and more attention. The complexity and variability of the network environment and the fragility of the information system determine that computer networks can not only rely on firewalls, but also involve management and technology.

Generally speaking, network security is not only a technical problem, but also a security management problem.

It is necessary to comprehensively consider safety factors and formulate reasonable objectives, technical schemes and relevant supporting laws and regulations.

There is no absolutely safe network system in the world With the further development of computer network technology, network security protection technology will inevitably develop with the development of network applications.

It is necessary to carefully consider the security requirements of the system, establish the corresponding management system, and combine various security technologies and management methods to generate an efficient, universal and safe computer network system.

Network security and preventive measures II

Abstract: With the popularization of computer network, we are more and more dependent on the network.

The openness of the network has threatened the security of network information as never before.

We must actively take various effective preventive measures to ensure that important information is not lost.

This paper mainly analyzes the hidden dangers of computer network security and discusses its preventive measures.

[Keywords:] computer network; Network security; Preventive measures; firewall

With the development of high technology, information technology has penetrated into various fields and played an increasingly important role in industrial modernization.

In particular, the extensive penetration and development of information technology in life has not only changed the traditional way of life, office and management.

As the core content of social development, informatization has become a booster to promote social development.

However, with the gradual expansion of information network scale and the deepening of system application.

A variety of network security issues have followed.

For example, the system is unstable, the network speed is slow or paralyzed; Failures such as login failure, equipment and information security accidents, hacker and computer virus intrusion have seriously affected the normal use of the network and become bottlenecks that hinder the further deepening and development of the network.

Therefore, it is of great significance to study the network security prevention technology.

1 the concept of computer network security

Network security is essentially information security on the network, that is, to protect the hardware, software and data of the network system from being destroyed, changed and leaked, the system runs reliably and normally, and the network service is slightly interrupted; From the user's point of view, they hope that personal and commercial information will be protected by confidentiality, integrity and authenticity when transmitted on the network, so as to prevent others from using eavesdropping, tampering and denial to harm and infringe their own interests and privacy; From the perspective of network operators and managers, they hope to protect and control the access, reading and writing of local network information to avoid viruses, illegal access, denial of service, illegal occupation of network resources and hacker attacks.

Computer security is mainly the technical and management security protection for establishing and adopting data processing systems, so as to protect computer hardware and software data from being destroyed, changed and leaked by accidental and malicious criminals.

Network security essentially includes the security of the hardware and software that make up the network system and the information transmitted on the network, so that it will not be destroyed by accidental or malicious attacks.

Network security has both technical problems and management problems, which complement each other and are indispensable.

2 network security risks

There are many factors that cause computer information insecurity, including human factors, natural factors and accidental factors.

Among them, human factors refer to some lawless elements taking advantage of loopholes in computer networks, or sneaking into computer rooms, stealing computer system resources, illegally obtaining important data, tampering with system data, destroying hardware equipment, and compiling computer viruses.

Human factors are the biggest threat to computer information network security.

The unsafe factors of computer network are mainly manifested in the following aspects:

2. 1 computer network vulnerabilities

Internet is an open network to the whole world, and any unit or individual can conveniently transmit and obtain all kinds of information online. The characteristics of Internet, such as openness, entertainment and internationality, pose a challenge to computer network security.

When using the Internet, you should pay attention to the following unreliable security.

2. 1. 1 The openness of the network and the complete openness of the network technology make the network face attacks from many aspects.

It is either an attack from physical transmission lines, an attack on network communication protocols, and an attack on computer software and hardware vulnerabilities.

2. The internationalization of1.2 network means that the attacks on the network come not only from users of the local network, but also from hackers from other countries on the Internet. Therefore, network security is facing the challenge of internationalization.

2. 1.3 The network is free. Most networks have no technical constraints on users' use, and users can surf the Internet freely, publish and obtain all kinds of information.

2.2 security problems in the operating system

Operating system is the supporting software, and it is the environment for normal operation of computer programs or other application systems.

The operating system provides many management functions, mainly managing the software resources and hardware resources of the system.

The unreliability of operating system software itself is a defect left by poor computer system development and design, which has left hidden dangers for network security.

2.2. 1 operating system architecture defects.

The operating system itself has memory management, CPU management and peripheral management, and each management involves some modules or programs. If these programs have problems, such as memory management problems, and one of the external networks is only connected to a defective module, the computer system may crash.

Therefore, some hackers often attack the imperfection of the operating system, which immediately paralyzes the computer system, especially the server system.

2.2.2 Operating system supports transferring files, loading or installing programs, including executable files, on the network, and these functions will also bring unsafe factors.

A very important function of the network is the file transfer function, such as FTP. These installers often bring some executable files, which are all artificially written programs. If there is a loophole somewhere, the system may crash.

Like these remote calls and file transfers, if the manufacturer or individual installs spyware on them, the whole transfer process and use process of the user will be monitored by others, and all these transferred files, loaded programs, installed programs and executed files may bring security risks to the operating system.

Therefore, it is recommended to use as little as possible some software of unknown origin or whose security cannot be proved.

2.2.3 Operating system has the protection function of daemons, which are some processes of the system and are always waiting for certain events.

The so-called daemon is the monitoring software that monitors viruses. When viruses appear, they will be caught.

However, some processes are viruses, which will format the user's hard disk under certain circumstances. These processes are very dangerous daemons, which may not work at ordinary times, but will work after they happen under certain conditions.

If people destroy the operating system daemon, this bad security risk will appear.

3 network security precautions

The above has analyzed a series of hidden dangers of network security, including the fragility of the network itself and some reasons for improper management.

As computer users, we should actively take effective measures to prevent problems and avoid possible serious consequences.

The main preventive measures taken for network security are as follows:

3. 1 Improve safety awareness and strengthen safety management.

(1) Equipped with professional safety management personnel.

There should be a special person in charge of safety management, and at the same time there should be technicians to implement it.

(2) Control the access and use of the network.

The purpose of controlling users' access to and use of the network is to ensure that network resources are not illegally used and accessed.

(3) Enhance anti-virus awareness.

Detecting and killing viruses is an indispensable and important means to ensure the security of network systems.

(4) Make timely data backup to ensure the safety of network information.

3.2 Timely repair of "loopholes"

Network software can't be without defects and loopholes, which are the first target of hacker attacks.

3.3 Using network security technology

3.3. 1 firewall technology

At present, one of the most important means to protect network security is to build a firewall.

Firewall is an image, which is actually a combination of computer hardware and software technology, that is, building a protective layer between the protected network and the external network to keep attackers out of the protected network.

This technology forces all data flows in and out of internal and external networks to pass through this security system.

By monitoring, restricting or changing the data flow through the firewall, it shields the information and structure of the protected network from the external network as much as possible, thus realizing the security protection of the network.

Therefore, firewall can be regarded as an access control mechanism, which is used to realize the security of LAN in unsafe public network environment.

3.3.2 Identity authentication

Authentication is an important part of any secure computer.

Identity authentication must accurately identify each other, and at the same time provide two-way authentication, that is, mutual proof of their identity. Identity authentication in the network environment is more complicated. Because the two parties verify their identities through the network instead of direct contact, the traditional fingerprint means can no longer be used, so at present, the methods based on symmetric key encryption or public key encryption and high-tech means of cryptography are usually used for identity authentication.

access control

Access control, also known as access control, prevents unauthorized users from entering the network and any unauthorized access to computer resources and communication resources.

That is, according to the user's identity, the user is given the corresponding authority, that is, whether the subject's access to the object is legal or not is determined according to the predetermined rules.

Access control is mainly realized through three levels: registration password, user grouping control and file permission control.

3.3.4 Cryptography-based technology

Cryptography is an interdisciplinary subject integrating mathematics, computer science, electronics and communication, and it is one of the main means to protect information security. It not only has the function of information encryption to ensure the confidentiality of information, but also has the functions of digital signature, identity verification, secret sharing and system security.

(1) key technologies.

The task of key technology is to control the selection and distribution of keys in cryptographic systems.

A key is a piece of digital information that interacts with an encryption algorithm to control the encryption of information.

(2) Digital signature.

Digital signature is an important identity authentication technology.

A digital signature is a number that depends on all the bits and keys of the message.

Its correctness can be verified by public key.

Digital signature can be used for authentication service, integrity service and undeniable service.

When digital signature is used for non-denial of service, it is used together with notarization.

Notarization is to verify the message through a trusted third party.

(3) Verification technology.

Authentication technology can be divided into authentication based on * * * shared key and authentication based on public key.

The former actually implements a query-question-answer protocol. The sender sends a random number to the receiver, and the receiver decrypts it and converts it into a special form and returns the result, thus realizing authentication.

The key of this protocol is how to establish a * * * shared key.

Antivirus software

Even with firewall, authentication and encryption measures, people are still worried about being attacked by viruses and hackers.

With the development of computer network, there are more and more data packets and emails carrying viruses and hacker programs. When these files are opened or run, the computer may be infected with a virus.

If anti-virus software is installed, some viruses and hacker programs can be stopped and found.

In a word, network security is a complex system engineering, involving many factors such as technology, equipment, management and system, and the formulation of security solutions needs to be grasped as a whole.

The network security solution is to integrate various computer network information system security technologies, including security operating system technology, firewall technology, virus protection technology, intrusion detection technology and security scanning technology, to form a complete and coordinated network security protection system.

Both management and technology must be paid equal attention, and security technology must be combined with security measures, strengthen network legislation and law enforcement, establish backup and recovery mechanisms, and formulate corresponding security standards.

In addition, because technologies such as cyber virus and cyber crime know no boundaries, it is necessary to carry out sufficient international cooperation to deal with the increasingly rampant cyber crime and cyber virus and ensure network security.

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