Security

Defining "computer security" is not a big thing. The difficulty lies in developing a definition which is wide sufficient to be valid regardless of the system being elaborate, yet specific sufficient to describe what security originally is. Within a generic sense a security is freedom from risk or danger. Security is the prevention of or protection against Inside the context of computer science,

• Access to information through unauthorized recipients
• Intentional but alteration or unauthorized destruction of that information.

This can be stated again: "Security is the ability of a system to protect information and system resources within respect to confidentiality and integrity." This should be remember in which the scope of this second definition involves system resources that involve CPUs, disks, and programs, further information.

Being a multi-user operating system, UNIX has incorporated several security measures at various levels to ensure total safety from any unauthorized access to the system. This session deals with two categories of UNIX security,

1) File level security or

2) System level security.