Data Security

There are a variety of security measures that can be used to protect hardware (the physical components of a computer system) and software (programs and data) including:

1. Controlling physical access to hardware and software.

2. Backing up data and programs (storing a copy of files on a storage device to keep them safe).

3. Implementing network controls such as:

a) using passwords (a secret code used to control access to a network system)

b) installing a firewall (a combination of hardware and software used to control the data going into and out of a network. It is used to prevent unauthorized access to the network by hackers).

c) Encrypting data (protecting data by putting it in a form only authorized users can understand)

d) Installing a callback system (a system that automatically disconnects a telephone line after receiving a call and then dials the telephone number of the system that made the call, to reconnect the line. It is used in remote access systems to make sure that connections can only be made from permitted telephone numbers).

e) Using signature verification or biometric security devices (security devices that measure some aspect of a living being e.g. a fingerprint reader or an eye scanner).

4. Separating and rotating the computing functions carried out by employees and carrying out periodic audits of the system i.e. observing and recording events on the network systematically.

5. Protecting against natural disasters by installing uninterruptible power supplies (battery backup systems that automatically provide power to a computer when the normal electricity source fails) and surge protectors (electronic devices that protect equipment from damage due to a sudden surge in a power supply).

6. Protecting against viruses by using antivirus programs (computer programs or sets of programs used to detect, identify and remove viruses from a computer system) and ensuring that all software is free of viruses before it is installed.

Particular care must be taken when using public domain software (free software) and shareware (software that is free to try out but must be paid for it is used after the trial period).

A smart card is a plastic card containing a processor and memory chip. It can be used to store large amounts of confidential data including coded data that can be used as digital cash (electronic currency that is used for making electronic purchases over the Internet). It can also be used as a security device to prevent or allow access to a system and allow a user to withdraw cash from a bank ATM (automatic teller machine – a type of machine used by banks for enabling customers to withdraw money from their bank accounts). A smart card reader is a device used for reading smart cards by detecting radio signals emitted from a radio antenna (aerial) in the form of a small coil inside the smart card.

An anti-virus program is a program that checks files for virus coding instructions inside another program and can be used for removing any virus coding instructions detected.

A backup program is a program that stores a copy of data on a storage device to keep it safe. There are different kinds of backup, including:

a) Incremental backup which copies all the selected files that have been created or changed since the last full, differential or incremental backup. These files are identified by the fact that their archive bit would be on. The archive bit is a digital bit stored with a file indicating if the file has been backed up since it was last edited. The archive bit is switched off when the file is backed up using a full or incremental backup.

b) Differential backup which copies all the files created or modified since the last full backup. The archive bit is not set to ‘off’ by a differential backup.

c) Full backup which copies all the selected files on a system, whether or not they have been edited or backed up before.

A series of incremental backups and a full backup, or the most recent differential backup and a full backup, is known as a backup set.