Threats to data stored on a computer
ICT systems have to be protected from a number of threats. Someone may access a system illegally in order to read sensitive information and, even though they may not cause any damage to the system, they may create all kinds of problems to the organisation. Worse still, they may actually change data or even delete it.
The main aims of security are:To maintain the system as intended
To protect the system from unauthorised changes being made to the software or data
To protect the system from both accidental and deliberate illegal access
To detect successful and unsuccessful attempts at illegal access
To provide a means of recovery if things go wrong.
Viruses are a small computer program that can cause damaged to a computer system. Viruses can cause a lot of damage to software, by deleting and altering programs and data. They can be spread from one computer to another through a network system, or on disks.
If a disk becomes damaged then the data stored on it may be lost. This can be true of fixed hard disks as well as all the removable media. It is sometimes possible to recover data from a disk, even if some of it has been corrupted. But to protect against the loss of data, all disks should be backed up regularly.
Back up procedures
The main aim of security is to maintain the system hardware and software as intended. So if things do go wrong it is important to be able to re create the system that existed before the damage was done.
It is far more difficult to replace data. But if proper backup procedures have been followed then the data can be copied from the backups and the system can revert to how it was before.