Operating systemA system having basic kernel functions of process and memory management ,file, i/o device and network management functions and many other functions.

Protection of memory and resources from any unauthorized into the PCB or resource ,or mix up of access of one by another becomes imperative.

Introduction to OS security issues

The OS security issue is a critical issue.

Each process determines whether it has a control of a system resoure exclusively or whether it is isolated from the other processes or whether it shares a resource common to a set of processes.

The OS then configures when a resource is isolated from from one process and a resource is shared with a defined with a define set of processes.

The OS should also have the flexibility to change this configuration when needed, to full fill the requirements all the process.

For example, a process has 32 memory blocks at an instance and the OS configures the system accordingly.

The OS should provide protection mechanism and implement a system administration(s) –defined security policy.

An application software programmer can find a hole in the protection mechanism and an unauthorized access.

Important security issues Protection mechanism

Flexibility to of change.

Control resource sharing

Confinement mechanism

Security policy (strategy).

Authentication mechanism.

Authorization.

Encryption

Protection Mechanism

OS should provide protection mechanisms

and implement a system administrator (s)

defined security

Flexibility to of change when needed to fulfill the need

requirements of all the processes.

For example, a process has control of 32

memory blocks at an instance and the OS

configured the system accordingly. t

Later when more processes are created, this

can be reconfigured.

Controlled resource sharing Controlling read and write of the resources

and parameters by user processes.

For example, some resources write only for

a process and some read only for a set of

processes

Another example, memory buffer to which

one process writes at an instant till that

buffer is emptied by other process

Confinement Mechanism Mechanism that restricts sharing of

parameters to a set of processes only .

Security Policy (Strategy) Rules for authorizing access to the OS,

system and information.

A policy example is that a communication

system may having a policy of peer-to-peer

communication (connection establishment preceding the data packets flow).

Authentication Mechanism External authentication mechanism for the user

and a mechanism meant to prevent an

application run unless the user registers and the

system administrator (software) authorizes

Internal authentication for the process, and the

process should not appear (impersonate) as some

like other processes.

User authentication can become difficult if the

user disseminates password passwords or other

authentication methods

Authorization User or process (s) allowed to use the

system resources as per the security policy

Encryption A tool to change information to make it

unusable by any other user or process unless

without the appropriate key is used for

deciphering it.

CONCLUSION

OS security issues are important

considerations.

Protection of memory and resources from

any unauthorized and without explicit

authorization write into the PCB or

resource

Mix up of accesses of one by

another, becomes imperative from an OS

security and protection mechanism