--Originally published at The shield of the world
So let’s start with this…
What is security in OS?
Is when you have issues external to OS and you would ask, why external? Because is the authentication of you, the user, validation of messages, malicious or accidental introduction of flaws, etc. So is not really about the OS.
And what is Protection in OS?
Mechanisms and policies to keep programs and users from accessing or changing stuff they should not do. AND is internal to OS. The OS has to provide this.
So…Protection and Security
An Operating System (OS) is an interface between a computer user and computer hardware. An operating system is a software which performs all the basic tasks like file management, memory management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers. We will call this objects.
And each object has a unique name and can be accesses through a well-defined set of operations.
Protection and security ensure that each object is accessed correctly and only by those processes of authorized users that are allowed to do so.
OS designers faces challenge of creating a protection scheme that cannot be bypasses by any software that may be created in the future.
Networking adds to the problem as it allows access to a computer and its resources without being in the same physical location.
This is the correct way to access and use Resources.
OS have goals like:
- Data confidentiality
- Data integrity
- System availability
And each of this has a threat:
- Exposure of data
- Tampering with data
- Denial of service
One of the solutions is user authentication…you know when you type “password” to actually enter your PC and if you don’t type anything and just has all his information without any little layer of protection should use at least a





