System And Network Security Computer Science Essay

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

Decades ago when the computer system was used very rare, no worries was for security, but later on when big companies and organisations start to use computer system on commercial bases and communicate through network the risks for data and information increased. In 1970s first time the computer security was considered in proper way, though the issues had prejudiced the progress of number of previous systems such as the Atlas system and MULTICS. Today the organisations are connecting their systems diagonally enterprise-wide networks and virtual private networks (VPNs), as well as growing their experience to clients, competitors, browsers and hackers on the internet. So the security for all these purposes is playing a vital roll. David Bell and Leonard La Paula have build up a replica for safe computer operations in early 1970s. The model was based on government concepts of different levels of confidential information (unclassified, secret and top secret) and various levels of authorization. According to that a person can obtain or can reach to a file if he permitted by the classification of file type. If the file has a privileged categorization than the user clearance classification then he or she can not access the file. Every corporate or organisation have different types of file access for its users and business partners. The existing idea is personified in the general criteria. Security measures should be clear to over come the problems for computer systems no matter in which environment they are.


1. Introduction:

The object of network system security is to facilitate the users instead of to keep them away from the system, network or information. However the system permitted the users to use this system to acquire information in a proper way. Good security measures gives confident to end users. In addition, by this high trust you can give secure entrance to out spiders like, your suppliers, clients, business partners, manufacturers, workers, consultants and contractors. (Rhodes-Ousley, 2004). Securing your existing system on different types of networks is vital for you, because most often these systems are linked with internet for commercial, research or study works and the hackers always attacks on the network to grab the information, but a secure network equipped with latest technologies can stop them. Twenty years before number of internet users was very low, so the hacker's attacks were also limited to network. But from last 10 years the use of internet extensively used on enterprise level, like social networking, online banking, online shopping. Both, the users and companies facing problems in this regard, so the network security technologies are essential to protect the internet and online transactions. (Pandya, 2010). "Measures adopted to prevent the unauthorized use, misuse, modification, or denial of use of knowledge, facts, data or capabilities" (Maiwald, 2004). Here I will introduce that the network and system security are very important due to higher no of internet users. Firstly, some benefits of security. Secondly, identifying some potential risks to network. Thirdly, some threats for network. Furthermore, principles and practices and finally, security technologies.

2. Benefits of System and Network Security:

In the real world system and network security has number of benefits for the companies and users, but two are the main.

2.1. Agility:

The number one is business agility; it means that how rapidly a company or industry can extend all the way through a protected system or network. Almost every organization or company trying to illustrate its business performance to its users, suppliers and business partners to attract more people to generate more profit. A car maker company for example, want to tap the individual users to increase the sale through their web site and web sites need a link for back end possessions, like account system, purchaser record and substance and supply schedule. The users can be permitted by the company to enter or login to their web site through a secure network system.

2.2. Return on Investment:

Company have many benefits that authenticate its resources and return on investment (ROI) can coherent in many ways. A positive image of a security program could be cooperative to increase money and calculate its effectiveness as well. It is difficult to assess the network or information system as a risk management. A web server use to carry out business online, usually organizations procure a web server on cash and think it is not valuable for business, but trade could not run online without the web server. A company bought a web server for £ 4500 for example and company get orders of £ 11,000 on line by using this web server, then its ROI assume 100%. Cost management is very important for achievement (Rhodes-Ousley, 2004).

3. Identifying Potential Risks for Network:

It is the duty of a risk analyst that he or she has to recognize the risks for the system or network security, network resources and information. The main objective of a risk analyst to identify the network mechanism, assess the value of each element and then apply the suitable level of security. The analysis is helpful to keep an effective balance between security and compulsory network access. What should need to secure on what cost is the key element. For example a high priced vehicle needs more money and resources for security than an old Junker. There are three types of assessment.

3.1. Asset Identification:

It is necessary to indentify the individual components through which the network made, before the network can be secure. All network devices and endpoints need to be listed, like servers and hosts. 3.2. Vulnerability Evaluation:

Vulnerability evaluation can be assessed after identifying the components of system or network. The identified vulnerabilities could be weak point in the equipment, configuration or security strategy. If you find out any vulnerability in the system, it must be addressed to lessen any threat that might be getting benefit of the vulnerability. There are number of methods to mend the vulnerabilities, by applying software patches, reconfiguration of devices or by installing or deploying countermeasures, such as firewalls and antivirus software.

3.3. Threat Identification:

Threat can be harmful for network system if there is any vulnerability found on system. Possible threats for network should known and the associated vulnerabilities need to be listed to control the risk.

4. Threats:

The network system also has some potential threats, which can destroy the system some time completely or some time partially.

4.1. Disruption:

A sector or entire network possibly will stop working, as the router or switch can stops communication as the power failure in this situation data can be lost or damage. Furthermore viruses are the most dangerous threat for the computer system or network. They normally attack on imitative storage drives, so the network may be stops working and information can be lost. In addition the computer system or network will perform tasks very slow.

4.2. Unauthorised access:

Unauthorised access is another issue for network, unauthorised people can enter into the system and can obtain the data for example, company’s important files, database, email or web servers they did not allow to access. The attackers can be from inside or outside from the organisation as well. Before the internet the networks were protected from outsiders and general people. The use of internet highly increased from the last 10 years, so it is very easy and normal to attack on an institutional or commercial data network. Hackers or unauthorised persons can easily watch the online transactions by entering into the system and can take your debit or credit card numbers, social security and driving license numbers and other important information. No doubt that the network or computer system security is better than before, still the ratio of attacks on networks amplified as well because security breaking equipment easily available online. (Pandya, 2010).

4.3. Denial of Services (DOS):

One of the most critical issues is denial of services (DOS). In this type of attacks the hackers enters into the network or computer system and can discontinue or destroy the network systems and their main aim is to stop services for users. They also can remove or modify the information simply by running a hack or script.

4.4. Viruses, Trojan Horses and Worms:

Different types of malicious software such as Worms, viruses and Trojan horses can be harmful for a system or network if it is not secured by appropriate solutions. Hackers through nasty software onto a system to demolish a system, corrupt a system, to get the important information on your system or deny services to enter into the network.

4.4.1. Viruses:

Basically virus is written cryptogram and they attached with a program or software and make it infected so when user open this program the virus also run on that system. So a virus is self-replicating and self-executing. It can be comes with a downloaded program or as e-mail (Cole, 2009).

4.4.2. Trojan Horses:

Trojan horse also a program and can be hidden inside the useful program and normally it have spiteful purpose. The main deference between virus and Trojan is that it is not self-replicate. Furthermore Trojan horses can found a back door which can be broken by hackers. Trojan horses for example, can plan to open a high-numbered port and that can be captured and system becomes more vulnerable for hackers.

4.4.3. Worms:

Worms work differently form viruses as they do not glued with host files, however they are self-reliant programmes or software and spreads on all network and computers. Worms usually spreads by e-mail attachments, as the user open the e-mail they also activated on the system. The distinctive

Worms engaged in sending a copy of itself to all users in contaminated computer's e-mail address book. The e-mail servers can be over loaded as they spread all over the network and can cause the denial of services (Cole, 2009).

5. Security Technologies:

Computer or network systems are vulnerable and security is essential to protect them from unauthorised users, viruses and hackers. There are many different technologies are now a days using by it professionals.

5.1. Firewalls:

"A firewall is a network access control device that is designed to deny all traffic except that which is explicitly allowed" (Maiwald, 2004). There two main kinds of firewall using in system.

5.1.1. Packet Filtering Firewalls:

The application layer firewalls are software programs or packages and it performed their duty on the top of general usage operating systems (UNIX or Windows NT) or on firewall appliances. A firewall can have number of crossing point and every network connects with its associated interface. A set of rules will monitor and classified the oncoming traffic on the internet. Unauthorised packets will be refused by the firewall. The proxies are responsible to impose the rules and regulations for packet filtering. The protocols which are running on an application layer firewall should have their own proxy (Maiwald, 2004).

5.1.2. Stateful Packet Inspection:

Stateful packet inspection is a state when firewalls merge stateful inspection with packet inspection. Stateful inspection not only based on packet organization and information enclosed in the package; however it is also based on what dialogue among hosts is in. It allows firewalls to filter traffic in both ways the contents of packet and the connection or state in which state the connection at the moment. In this way it provides more supple maintainable and scalable result. When a link has been recognized and allowed then it is not required to describe a rule for returning traffic or as the firewall knows through the state when a usual response should be (Noonan and Dubrawsky, 2006).

5.2.Virtual Private Networks:

The organisations use the private network to correspond with isolated sites and other organisations. ISPs and different phone companies offer the lease lines to establish a private network. These rented lines are work directly and the bits which travel through them are segregated from other traffic as these lines make a real route among the two sites. There is the number of benefits of private networks.

The data will be safe

Isolated sites can swap information immediately

The users are at distance not feel lonely

Private networks have a big disadvantage as well and it is "COST". These types of networks are very expensive. Company can save money by using slow lines, but the remote user feel that there is no speed so some of the advantages start to disappear (Maiwald, 2004).

5.3. Cryptography:

Cryptography is a term which means to encrypt data from unauthorised users and decrypt this data again when it reaches to its destination. Term plaintext means a unique message, on the other hand the implied message known as chipertext. When a system changes a plaintext into chipertext this procedure call enchipring or encryption, and when a wise versa of encryption do it is called dechipring or decryption. The number of ways or rules used to encryption represents it is called cryptography. It is also called a cryptographic system or a chiper scheme. It has five types.

5.3.1. Plaintext:

It is the real understandable message or information that is sent to the algorithm as input.

5.3.2. Encryption Algorithm:

It will apply dissimilar algorithms to execute different substitutions and alteration on plaintext.

5.3.3. Secret Key:

It is also input to the encryption algorithm. The precise substitutions and conversion attempted by the algorithm depend on the key.

5.3.4. Chipertext:

It is the twisted or encrypted out put of plaintext. It is depend on text and the key.

5.3.5. Decryption Algorithm:

The encryption algorithm should run in overturn. It will obtain the chipertext and the secret key and then generate the real plaintext (William, 2011).

Research Question:

All these technologies are using in world of internet and security are at there peak. Every organisation trying to use the latest technology, software and hardware to protect there vulnerabilities. However there are still some gaps are exciting to full fill them and important data or information need to secure from hackers because as the technology growing day by day the hacker or attackers also getting strength to steal the data.

Q. Is the e-mail and the online transactions are completely secured?

Q. Are the security technologies available in market are reliable for the big organisation and domestic users as well?

Q. Are the open networks like Wi-Fi are protected trough mobile devices?