Page 292 - DCAP103_Principle of operating system

Unit 9: System Security

Objectives Notes

After studying this unit, you will be able:

• Explain security problem

• Understand program threats
• Explain system threats

• Understand network threats

• Discuss cryptography
• Explain user authentication

• Understand implementation of defenses

• Discuss firewall

Introduction

It is unnecessary to say that all operating systems are not equal in every sphere. None of the most
accepted operating systems now-a-day are developed keeping safe and sound electronic business
in mind. From the moment the computer is booted (after loading the BIOS), the interaction
with the operating system starts. This essential portion of software describes what can be done
with the system of the computer and how it is to be done. Whether the interaction is with the
file system or while chatting with somebody with the help of an instant messenger line up, the
operating system works at the back of the pictures to provide with a perfect experience as it
understands the procedures and changes them into those things that the computer can process.
Even as operating systems differ on a lot of levels, the most ordinary operating systems offer
much more than an easy crossing point between the user and the machine.
These include many programs with the intention to provide the user with many extras, starting
from the straightforward screen savers to multifaceted file-encryption plans. However, it’s vital
to know that these programs are add-ons which are added on to the OS and are not essential for
the computer to function. A lot of users become closely familiar with the operating system’s frills
(such as the Solitaire), but do not remember about the security parameters that are incorporated
to help the user preserve a secure and dependable operating setting. And therefore, a lot of
information systems continue living in an insecure condition that keeps the system at the danger
of a virus infection or at the total compromise by a hacker. From creation a protected home
network to creating well-built passwords, it is very vital to know the particulars of using an
operating system in a secure and safe and sound mode. In today’s world, where the computer
is an essential gadget it is foolish to set up a computer devoid of the security system. It is only
one virus or Trojan horse that is enough to form a concurrent consequence of contaminated
computers and compromise systems.
UNIX which is the eldest and the mainly used networking operating system of today’s world
has got the benefit of having been patched and hacked by crackers and hackers for many years.
Amongst all other UNIX derivatives, the most popular derivatives is Linux, which was developed
by Linus Torvalds and now being maintained by a lot many of volunteers and a lot of software
companies. But this Linux still has got errors which are being discovered in a day-to-day basis.
It is tremendously significant to keep an eye on these incidences and use the essential patches

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