MTA 98-364 Theory: Data Security

Data security is about keeping data safe and affects anyone relying on a computer system. If the data on a computer system is damaged, lost, or stolen, it can lead to disaster.

Key threats to data security

Data may get:

• lost or damaged during a system crash - especially one affecting the hard disk
• corrupted as a result of faulty disks, disk drives, or power failures
• lost by accidentally deleting or overwriting files
• lost or become corrupted by computer viruses
• hacked into by unauthorised users and deleted or altered
• destroyed by natural disasters, acts of terrorism, or war
• deleted or altered by employees wishing to make money or take revenge on their employer

Keeping data secure

Measures that can be taken to keep data secure include:

• making regular backups of files (backup copies should be stored in fireproof safes or in another building)
• protecting yourself against viruses by running anti-virussoftware
• using a system of passwords so that access to data is restricted
• safe storage of important files stored on removable disks, eg locked away in a fireproof and waterproof safe
• allowing only authorised staff into certain computer areas, eg by controlling entry to these areas by means of ID cards or magnetic swipe cards
• always logging off or turning terminals off and if possible locking them
• avoiding accidental deletion of files by write-protecting disks
• using data encryption techniques to code data so that it makes no apparent sense

Online banking

When you bank online, after you’ve logged in, you will notice that thehttp in the address bar has changed to https. This indicates that a secure connection between your computer and the bank's computer has been established. Data sent between the two computers is encrypted so that anyone trying to intercept your data will receive meaningless data. The data can only be decrypted into readable data by using a key that is known only to the two computers - yours and the bank's.

Questions on data security

QQuestion

In a local doctor's surgery, data about the patients is stored in a database on a computer.

Consider two physical precautions that should be taken to keep the data secure.

AHide answer

1. Keep the computer area secure
2. Keep backups in a safe place

QQuestion

The doctor needs to see all the information about patients. The receptionist only needs to see some of the information.

Describe one way in which software could restrict access to patient information.

AHide answer

Make it so users must enter a password to gain access to certain areas of the database.