It is essential to have adopted various prior protective measures for the safety and the durability of computers. The security of the computer system can be divided into two parts.

Any physical component of a computer that you can touch and see is called hardware. It has a definite shape. As there are hardware devices outside of a computer, there are hardware devices inside the system unit too.

Some main factors that may cause physical damage to hardware devices;

Figure 3.4 – Some steps that can be taken to protect the computer from physical harm

- By entering the lab without footwear, the computer lab can be kept free of sand and dust.

- Dust gathering on computer circuits (devices) can be prevented by cleaning all the computers in the lab at least once in every three months.

- Taking food in the lab can attract insects like ants to the food particles fallen on the ground

- Moisture in the laboratory may cause short circuit.

Data and information in the computer and programmes used for various tasks come under the category of software.

Example:

Operating System

Word processing software

Files containing documents

Files containing pictures / images

Some instances that may cause possible threat to software are mentioned below.

Malware is a main factor that can couse a threat against the security of computer software.

What is malicious software (malware)?

Malicious software can be defined as any man-made software or part of a software that functions against the requirements of the computer user and designed to intentionally cause damage to

• software installed in the computer

• data, information stored in the computer

• computer networks

• and perhaps computer hardware devices as well.

1. Computer virus

A computer virus is a main malicious software that gains entry to computer software and files and which is capable of replacating itself and designed to spread from computer to computer through portable devices. It can delete or modify data / information and it can corrupt software as well.

2. Computer worms

It causes damages similar to those of viruses. However, the main difference is that it spreads across computer networks or internet without the support of a host program or any human interaction.

3. Trojan horse

While it seems a useful software at first sight, it will cause damage to the user secretly once he begins to use it.

4. Spyware

It is a malicious software that secretly collects data about a person’s computer usage, internet usage and etc.., and sends them to the relevant party without his knowledge. Data and information too can be provided to the other party secretly through this software.

Keeping backups can be defined as a process of keeping copies of software components.

Copies kept as backups can be used in case the original copy is misplaced or damaged. Several storage techniques can be applied to keep backups.

eg:

Compact disks (CD)

Digital Video Disks (DVD)

external hard disks

Different location in the same computer (another folder or another drive)

Providing software solutions for access control

It means the methods and services provided by several software to control access to computer and safeguard its resources.

• Using strong and difficult to guess password

• Creation of suitable user accounts

• Encryption

By following the above mentioned methods, not only access to computer can be controlled but also data and information can be protected from sudden loss.

Use of physical locks for access control

The computer system, data and information stored in the computers and software are protected by using devices and methods that are in the form of hardware in this method.

For this, following methods are used.

1. Keeping the computer at a secure place.

It is advisable to keep the computer that contains sensitive and valuable data, information at a secure place, so that it will be protected from thieves and unlawful entry of people.

2. Use of CCTV cameras and alarms

Tasks such as monitoring movements when necessary, provision of automatic urgent messages are done by this system.

3. Use biometric passwords

At present, finger prints and voice recognition methods are widely used to access computer systems and to open doors of the computer laboratory.