5.1.6 Protecting Data

The risks to data:

The data stored in a computer can often be far more valuable than the actual computer equipment. Losing such data could put a company out of business.

Examples of valuable data are:

• a company’s financial records;
• customers’ details;
• records of company stocks and shares;
• data collected from experiments or research. 

Data can be damaged or destroyed in the following ways:

• mistakes by users such as deleting files
• hackers gaining access to systems and changing or deleting data
• computer fraud where data is changed to benefit individuals
• theft of computer hardware such as laptops with data on the hard disk(s)
• infection of systems and data by computer viruses.
• deliberate and malicious damage by users of the system, possible in revenge for being made redundant for example.
• disasters such as fire, floods, earthquakes etc. destroying equipment
• breakdown of hardware, particularly disk drives

Why computer data is easier to misuse than paper-based data:

Reducing the risks of data loss:

Making a backup of data:

Keeping hardware secure:

• Protect the computer itself by using locks on doors and windows and using security bolts to fix the computer permanently to the desktop.
• Laptops are often fitted with locking points so a cable can be used to secure them to a desk etc.
• Floppy disks are easily physically damaged and must also be kept away from magnetic fields and dust.

Illegal access to computers:

• Hacking involves breaking codes and passwords to gain unauthorised entry to computer systems. Once into a computer system a hacker can do an enormous amount of damage. Stand-alone computers are less of a risk as the damage is limited to just that computer. Computers which form part of a network or those with external links, such as attached modems, are at greater risk as they can be accessed from other computers.
• There are three levels of hacking, all of which are punishable by fines or imprisonment under the Computer Misuse Act of 1990.
  • accessing information without permission, even though it is only to view it (i.e. looking through someone's personal email)
  • accessing information and using it for illegal purposes (i.e. looking up details of a rival companies research projects)
  • accessing information and altering it for fraudulent purposes (i.e. altering financial details of customers in a bank)

Ways to restrict access:

• User Ids (user identification) and passwords
• Blocking external access - external hackers can be blocked by disconnecting modems from the telephone line when not being used. Systems with permanent phone connections need special software called a 'firewall' to try and prevent unauthorised access.

Computer viruses:

There are three things to remember when explaining what a virus:

• It is a program: a set of instructions which can be introduced into a computer via a floppy disk, email attachment or the Internet.
• It makes copies of itself: the program contains instructions that make it attach copies of itself to system files or programs. It can therefore spread to other programs on your hard disk and onto floppy disks or email itself to all the contacts in your email address book.
• It causes damage: the effects can be devastating and cost millions of pounds to fix. They can alter the host program, stop it working completely or damage the hard disk to become scrambled.

Under the Computer Misuse Act of 1990 it is illegal to deliberately infect a computer system with a virus and the offence is punishable by fines or imprisonment.

Protecting against computer viruses:

Anti-virus software is usually required to detect and then destroy them but it is important to have regular updates to deal with new viruses. The anti-virus software scans the computer's disks looking for any viruses which it then removes and alerts the user.

Protecting floppy disks - The 'write-protection' hole in the corner of the floppy disk can be kept covered to prevent accidental wiping of the disk or the introduction of viruses.

To reduce the risk:

• Never use a floppy disk given to you from an untrustworthy source or pass floppy disks around between your friends.
• Do not start up a computer with a floppy disk left in the drive.
• Set the computer BIOS so the boot sequence so it does not start with the floppy disk drive.
• Keep the write-protection hole covered on floppy disks that are used to store original "clean" programs - so they can be reinstalled with confidence.
• Never open an email attachment that comes from someone unknown or is not clearly explained in the email message that it is attached to. Even then BE SUSPICIOUS - virus program writers are always thinking of new ways to get computer users to open attachments and run the virus!
• Install a virus protection program and keep it up-to-date!
• Be careful of the websites you visit and the hyperlinks you click on.  Many websites are designed to trick visitors into downloading viruses, trojans or spyware. If you are unsure of a hyperlink, always hover over it with the mouse before clicking so you can see (in the bottom-left of the browser screen) where it will take you to.  i.e. Click here to view a funny video.

Click here for details on copying computer software and the law.