1. A-Level Computing data damage and prevention

2. Objectives To know the dangers associated with a computer system To understand the methods of prevention To be able to demonstrate the need for prevention methods

3. Privacy & Security What can cause damage to a computer system?

4. Privacy & Security Accidental & Malicious Damage Hardware failure - all hardware dies eventually. Software Failure - programming bugs Human Errors - hanging of data or deletion of files Malicious Damage - angry employee, a virus or a hacker.

5. Privacy & Security Any loss or corruption of data will have serious or fatal implications for the performance of the application Delays, loss of business and possible legal action may result.

6. Privacy & Security What can you do to prevent damage to your computer system

7. Privacy & Security Physical security Security Guards Alarms Locks Swipe/ID Cards Read/Write Tabs

8. Privacy & Security In order to gain access to the system a user is supplied with a user name together with a personal password. Operating system will check the user name and password are valid before allowing the user to log in. Some files may be open by anyone, others only by those users with a particular level of access.

9. Privacy & Security The file itself has attributes that can be set. The commonly used ones in Windows are: Read-only - the file can be read but not altered Hidden - the file is not displayed in listings of files.

10. Privacy & Security Computers connected to networks - especially the Internet - need to be protected from hackers. Firewalls are software methods of blocking access to anyone from outside a network unless they are authorised.

11. Privacy & Security To maintain file security when data is transferred from one computer to another the data can be encrypted. This means that the data is encoded in some way before it is sent, and therefore meaningless to anyone intercepting the message. The data is then decoded at the receiving end by the user who knows the way to decrypt it (often referred to as the key).

12. Privacy & Security Key - next letter along in alphabet: IFMMP XPSME HELLO WORLD Data encryption can also be used when data is stored on a file. A hacker accessing the data will find it meaningless unless he has the key.

13. Privacy & Security Important files of data should be regularly backed up - this means making another copy of the data and storing the copy in a different place. Many organisations run a daily backup - scheduled to run overnight, but backups can be done any time. Backups may be stored on the same computer - but it is better to store them on a different one.

14. Privacy & Security Backups of data may also be stored on backing storage media such as CD, DVD or tape cartridge. The backup copies should be stored securely - a locked room or a fire-proof safe. As broadband Internet access becomes more widespread, backups to remote sites are becoming more popular.

15. Privacy & Security If data is accidentally or deliberately lost or damaged, the backup data should be loaded. All changes to the data since the backup was made will need to be done again.