System security

System security

1. Security on single-user systems is different from security on multi-user systems

   • Single-user security involves protecting files of data from accidental change or deletion
     • There is less need for protection from unauthorised users than there is on a multi-user system or network

2. Other software may be installed

   • Which protects the files on a computer from being changed by viruses

3. Some of the security measures that might be taken by the operating system

   • On a multi-user system, the username and password are checked every time a user logs on to make sure they are authorised
   • A log is kept of computer usage. The time when a user logged on and how long the user used the computer are recorded
   • The time and date when a file was last changed are recorded. This means if a file has been deliberately changed, it may be possible to track down who was using the computer at the time
   • The attribute of a file can be set to “read-only”. This would make it impossible to accidentally change or delete an important file
   • If a file is deleted, it may be put into a “recycling bin” and if the user discovers that a mistake has been made then the file can be recovered
   • Tasks such as taking back-ups can be scheduled to occur at regular times

4. One of the tasks of an operating system is to maintain security

   • This means protecting the system from malicious or accidental damage by users
   • Damage may involve changing a data file or even deleting it

5. In practice, a combination of security measures needs to be in place

   • It is worth remembering that the security of a system is only as strong as its weakest link

6. For example

   • It would be no good having really strong protection against viruses if the protection against hackers is weak