Computer Security And Confidentiality Computer Science Essay

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The computer is amazing machine to have, but in the same time it is a big responsibility to keep the computer in a good condition and protected it from the viruses so don't have to load useless information because that will make the computer slow down. Most of this information comes from what called "Cookies" which come when we use the internet. Most of these cookies are harmless and we can delete it very easy. But some time when access to the internet may the viruses catch the computer and causes damage the files. In this report I will try to give a brief account on viruses and how can we protect our computers.


On 9-11-2009 the Internet teacher Aoife Mc Carry requested a 1500 word report related to the FETAC Internet module. This report was to be submitted by 28-01-2010. The topic of the report is Security and Confidentiality on the Internet with reference to cookies, viruses, encryption, digital signatures, firewalls, filtering software and personal privacy.


Aoife the internet teacher asked us to make a search for "Security and Confidentiality on the Internet". I start looking up for information on websites such as ", Google, and" by using a key words like ( Virus, cookies, Encryption…etc ) these websites were the best help to me and they make the search easier. The information wasn't very easy that because the language that used so I collect all the information in a folder to read it, and after I understood it and I wrote it in my own way. It was rely good and useful information's and gave me good knowledge about computer and it security.


3.1 Cookies:

3.1.1 What are cookies?

Cookie is a text file saved to your hard drive by the website, and this file contains information about your search on the internet. It saved without your permission, when you visit the site next time it recognize you by looking up your cookie. These cookies are programmed to collect information about you.

Cookies are not malicious we can delete it easily.

3.1.2 How do they work?

Most Internet cookies are very simple, but they are one of those things that have taken on a life of their own. In the same time cookies has ability that makes the Web much easier to navigate. The designers of every major site use them because they provide a better user experience and make it much easier to gather accurate information about the site's visitors.

What are the advantages or disadvantages of Cookies?

The Advantages:

1. Cookies do not require any server resources since they are stored on your computer.

2. Cookies are easy to use.

3. You can configure cookies to expire when you finish with the


How could I prevent / manage Cookies?

How could I prevent Cookies?

Delete cookies on a regular basis: By delete the history in the internet browser. This will remove the

text files from the hard drive. The websites will crate a new cookie in the next time visiting the web but at least you can stop them from increase over your personal information.

Turn off cookies on your internet browser: You can set up your browser to refuse to accept cookies

from websites.

Choose to use that make privacy a priority: By choosing search engine that dose not use cookies.

How could I manage Cookies?

Click the Tools menu.

Select Options.

Click the Under the Hood tab and find the "Privacy" section.

In the Cookies setting menu select one of the following:

Allow all cookies.

Restrict how third party cookies can be used.

Block all cookies.

Click close.

Cookie management software:

Cookie Spook.


elMAGE Recovery.

3.2 Viruses:

3.2.1 What is a virus?

Viruses are a kind of software program that are designed or found to spread from computer to another without permission from the user. It slow down the computer programs progress, by causing damage and destroy data, and these programs can slow the internet work too.

These Viruses are dangerous because they are hidden and cannot be found and removed by normal ways.

Types of virus and Examples:

There are different types of Viruses.

A- Boot viruses:

Boot viruses affect the boot of floppy disk or hard disks. This is a very important part of a disk, which is responsible for loading the operating system in memory. They can replace the boot record program with copying it other place on the disk or overwriting it.

Boot viruses load into memory if the computer tries to read the disk while it is booting.

Examples: Form, Disk Killer, Michelangelo, and Stone virus.

B- Program viruses:

These infect the program files, (with extensions like .bin, .com, .exe, .sys and ovl). These virus loads in the memory during execution, taking the virus with them. The virus becomes active in memory, making copies of it self and infecting files on disk.

Examples: Sunday, Cascade

C- Stealth viruses:

These viruses can hide from antivirus software by cover the size of the file that it hides in temporarily removing itself from the infected file and make another copy in another place on the drive. And replace the infected file with one uninfected which has stored on the hard drive.

Examples: Frodo, Joshi, Whale

D- Polymorphic viruses:

A virus that can change it signature every time and appears differently next time it will appear and infect a new file to avoid finding by antivirus program.

Examples: Involuntary, Stimulate, Cascade, Phoenix, Evil, Proud, Virus 101

How can computers become infected?

There are many different ways that the computer is infected with spy ware and viruses. And these are the most common ways to infect the computer.

Accepting without reading

When you accept what see on the screen without reading and understand what it's asking. For example: While browsing the Internet some Internet advertisement appears saying your computer is infected, and without rely understand what it is about you accept the prompt.

Opening e-mail attachments:

By opening e-mail attachments, E-mail address can faked very easy, and even not faked it can be carrying an infected file.

When we receive an e-mail with attachment we have to delete it if we do not know the person that send it and we have to do the same if the attachment from person that we know we have to scan it first.

Pirating software, music and/or movies

When downloading or copyrighted music, movies, software, etc. for free, many of the files can contain viruses, spy ware and even malicious software.

Downloading infected software

When we download any software from the Internet can be contain viruses and other Malware.

What damage can viruses cause?

The computer virus can:

Change the way your computer operates

Cause your computer to crash and restart every few minutes

Slow down your computer's connection to the internet

Destroy or modify files

Format your hard drive so that it deletes all files and programs

Send fraudulent email to and from your computer

Permanently damage your computer

How could I prevent viruses? Mention software etc

Install an antivirus program in to the computers and be sure that is update regularly.

Secure the internet by using a firewall, and avoiding software from unreliable sources.

Scan any email attachments or any files downloaded from the Internet before you open them.

Not allowing users to take the company's disks home to use on their own PC.

Only use software that has been scanned by a virus checking program.

Not allowing other users to use their own floppy disks on your system.

There are many different software antiviruses

- Norton Antivirus

- AVG Antivirus

- McAfee Antivirus

3.3 Filtering Software?

3.3.1 What is it?

Filtering software designed to protect children from web sites containing pornography. The ability of the filtering software grew. Internet-filters are now used to block sites that supporter potentially disquieting and hurtful content and can be modified to suit specific user needs. 

Who needs them?

Parents need internet filtering software to protect their children from the unsafe websites on the Internet,

in the same time they want to know what the children are doing online, and look after their privacy. and

stop the horrible stuff from coming into their home.

Schools and libraries may use filters to put up a wall between children and internet threats.

How does it work?

Blocking of chat rooms and block newsgroups, IM ports and even personal information. You can set up individual user profiles with passwords. 

What are the advantages or disadvantages of Filtering Software?

The Advantages of Filtering Software:

Parents do not want their children watching violent, criminal, or sexually images and filters prevent it.

Some supporter said that filters achieve a almost porn-free online atmosphere.

Examples of Filtering software programmes.

1- The Hodrick-Prescott filter.

The Marcet-Ravn Version of the HP-filter

Solving Real Business Cycle Models

3.4 Firewalls

3.4.1 What are they?

Firewall: Is a computer system designed to divide the computer system on the Internet and the Internet as a whole. Firewalls are used to limit access of the system's users to the outside world, and vice versa, for security and economic reasons.

Who needs them?

A private network that is connected to a public network needs firewall protection.

Anyone who connects a single computer to the Internet via modem should have personal

Firewall software.

How do they work?

There are two way to denial methodologies used by firewalls.

A firewall may allow all traffic through unless it meets certain criteria, or it may reject all traffic unless it

meets certain criteria. The type of criteria used to find out whether traffic should be approved through

varies from one type of firewall to another.

Firewalls may be concerned with the type of traffic, or with source or destination addresses and ports.

They may also use difficult rule bases that study the application data to decide if the traffic should be

allowed through.

Advantages of Firewalls?

Using Firewalls will increase the feeling of security that your PC and filling are being protected.

Firewalls are quite cheap or free for personal use.

You can watch incoming and outgoing safety alert and the firewall company will record and track

down an intrusion try depending on the severity.

3.5 Encryption:

3.5.1 What is it?

Encryption is the most useful way to achieve data security. If you like to read an encrypted file

you must have secret key or password that allowed you to decrypt it.

How does it work?

There have been different types of data encryption techniques used to protect sensitive and personal

information. Briefly discussed are some of the past, current and future encryption methods used in the

United States.

Who needs it?

Everyone can get the profit from encryption software.

Everyone wants be comforted that their private's information remains secret.

Public key encryption protection can provide that reassurance.

3.6 Digital signature:

What are they?

It is the way to be sure that an electronic document is true or authentic, Authentic means that you know who created the document and you know that it has not been altered in any way since that person created it.

How do they work?

The Digital signature working as the fallowing each person has TWO keys, one private has to be keep it secret, and other one public which you can published online and paste on your website. Anyone who wishes to ensure that only you will open a message will need this.

Who needs them?

Public and private keys used to pass sensitive and important information and it can be used to provide authentication but not to provide confidentiality.

Personal Privacy:

Is there any such thing on the internet?

No there is no Personal Privacy on the internet.

If not, why not? Mention Emails as well as Browsing.

There are no privacy on the internet because we are not going to know if there are security in that website and hackers can broke down out security and gat our information and the use it. Like Facebook, Bebo.

4.0 Conclusions:

This search give me a lot information about the computer and understanding what the meaning of viruses and cookies how they work, and how can I prevent the computer from them, and I had an information on what the Filtering software, Firewalls…..etc, what they are and who need them.

Now I can protect my children and my computer.


Make sure you have the latest versions of antivirus.

Installing antivirus software can stop these problems with your PC and protect you from the hassle of

trying to recover everything you had stored on your PC

When you download (programs, games, etc.), you have be sure to download them from a reliable


The best way to clean the files from the virus that you have to delete the files which affected by virus.