1.3 Computer Security
Computer Security / Cyber Security
Computer
security means protecting our computer and its content from damage, theft or
misuse and action to prevent such incidents.
The
types of computer security are hardware security and software security.
Tips for Best Computer Security
a)
Use
the best antivirus software, which not only provides protection to your PC
but also internet protection and guards against cyber threats.
b)
Do
not download untrusted email attachments as these may carry harmful malware.
c)
Never
download software from unreliable sites as they may come with a virus that may
infect your system as soon as you install the software.
Possible threats to computer security
a)
Human
error
b)
Computer
crime
c)
Natural
disasters
d)
War
and terrorist activity
e)
Hardware
failure
Information Security (infosec)
Information
security is the practice of preventing unauthorized access, use, disclosure,
disruption, modification, inspection, recording or destruction of information.
Key principles of Information Security
a)
Confidentiality:-
Only authorized users can access the data resources and information.
b)
Integrity:-
Only authorized users should be able to modify the data when needed.
c)
Availability:-
Data should be available to users when needed.
Security Threats
— A risk which can
potentially harm computer systems and organization.
— The cause could be physical such as someone
stealing a computer that contains vital data.
— The cause could
also be non-physical such as a virus attack.
Possible Security Threats
— Internal: The threats
include fire, unstable power supply, humidity in the rooms housing the
hardware, etc.
— External: These threats
include Lightning, floods, earthquakes, etc.
— Human: These threats
include theft, vandalism of the infrastructure and/or hardware, disruption,
accidental or intentional errors.
— Loss or
corruption of system data.
— Disrupt business
operations that rely on computer systems.
— Loss of
sensitive information.
— Unauthorized
access to computer systems resources such as data.
Malicious code (Malware)
— Malicious code
is a kind of harmful computer code or web script that is planned to cause
undesired effects to damage a system.
—
Includes
computer viruses, worms, Trojan horses and spyware.
Types of malware
a)
A virus is
the most common type of malware which can execute itself and spread by
infecting other programs or files.
b)
A worm can
self-replicate without a host program and typically spreads without any human
interaction or directives from the malware authors.
c)
A Trojan horse is designed
to appear as a legitimate (valid) program in order to gain access to a system.
Once activated following installation, Trojans can execute their malicious
functions.
d)
Spyware is made
to collect information and data on the device user and observe their activity
without their knowledge.
e)
Keyloggers,
also called system monitors, are used to see nearly everything a user does on
their computer. This includes emails, opened web-pages, programs and
keystrokes.
Protect a system from infection
a)
Never
download files from unknown or suspicious sources.
b)
Install
antivirus software that features automatic updates and has the capability to
detect all types of infections.
c)
Delete
spam and junk emails without forwarding.
d)
Always
scan a pen drive from an unknown source for viruses before using it.
Security
mechanisms
— A mechanism that
is designed to detect, prevent, or recover from a security attack.
— It includes
— Authentication
Systems
— Firewalls
— Cryptography
— Antivirus
Software
— Backup System
Authentication System
— Authentication
is the process of verifying the identity of a person or device.
— Authentication
system makes sure that right people enters the system and access the right
information.
— Types of
Authentication
— Password
— Biometric
Password
— A set of secret
characters or words used to authenticate access to a digital system.
— Password secures
the data by protecting the data from unauthorized access.
— A password
should be difficult to guess and determine and should be changed regularly and
memorized.
— Password secures
the data by protecting the data from unauthorized access.
Any four criteria for strong password
are:
a)
Do
not keep a password which can be easily guessed such as date of birth, nickname,
etc.
b)
Do
not keep word as password that is currently popular.
c)
Keep
a password with mixture of alphabet and numbers which is difficult to guess.
d)
Keep
changing your password regularly.
Biometric
· Biometrics are
physical or behavioral human characteristics that can be used to digitally
identify a person to grant access to systems, devices or data.
· Examples of
these biometric identifiers are fingerprints, facial patterns and voice.
Firewall
A firewall is the network security systems that monitors and controls the
traffic flow between the Internet and private network or private computeron the
basis of a set of user-defined rules.
Firewall
blocks unwanted traffic as well as malicious software from infecting your
computer.
Cryptography
— Cryptography is the study of secure communications techniques that allow
only the sender and intended recipient of a message to view its contents.
— A message sent
over the network is transformed into an unrecognizable encrypted message known
as data encryption.
— At the receiving
end, the received message is converted to its original form known as
decryption.
— Cryptography is
used to secure and protect data during communication.
Encryption
— Encryption is a
process which transforms the original information into an unrecognizable form.
— Encryption is
done by the person who is sending the data to the destination
Decryption
— Decryption is a
process of converting encoded/encrypted data in a form that is readable and
understood by a human or a computer.
— Decryption is
done at the person who is receiving the data
Antivirus software
— Antivirus
software is software designed to detect and remove virus from computer system
and ensures virus free environment.
— E.g. Kaspersky,
NAV, MSAV, McAfee, NOD 32 etc.
Backup system
It is the system of copying data and programs into
another location or creating a duplicate copy of it in a secured place.
Backup is vital to computer security system in order
to save the data from being lost or damaged due to accidental or intentional
harm. When data and software are lost or damaged, we can easily recover through
backup.
Compuer virus
Computer
virus is a type of computer program which is written by the programmer with the
intent of destroying or damaging the data and programs residing in the computer
system.
E.g.
C-Brain, Frodo, Disk Killer, I Love You etc
The
purpose of creating computer virus are:
a)
To
stop computer piracy
b)
To
entertain user by displaying interesting message and pictures
c)
To
destroy data, information and files
d)
To
earn money
Spreading computer virus
a)
Sharing
infected internal portable disk like floppy disk, pen drive, CDs, etc.
b)
Opening
a virus infected email, messages and attached files.
c)
Downloading
files and programs form the websites which are not secure.
d)
Exchanging
data and information over a network
Symptoms of computer virus
a)
Program
takes long time to load.
b)
Increased
use of disk space and growth in file size.
c)
Corrupting
the system data.
d)
Renaming
files with different names.
Preventive ways to protect computer
system form virus
a)
Write
protect your floppy disks when using them on other computers.
b)
Scan
the mail or unknown files of internet before opening in your computers.
c)
Use
a good antivirus program to scan floppy disk, CD, etc. before copying.
d)
Don’t
install pirated software, especially computer games.
e)
Don’t
interchange the internal disk among the computers.
Types of viruses
a)
Boot
sector virus
b)
File
infector virus
c)
Multipartite
virus
d)
Stealth
virus
e)
Macro virus
Hardware Security
Hardware
security is the protection given to the various hardware tools and equipments
used in computer system from the accidental or intentional harm.
Different
hardware security measures are:
a)
Regular
Maintenance
b)
Insurance
c)
Dust
free environment
d)
Protection
from Fire
e)
Protection
from Thief
f)
Air
condition system
g)
Power
Protection device (Volt guard, Spike guard, UPS)
Regular Maintenance
Computer
system need regular maintenance to keep the computer hardware in good working
condition and it also helps to find out problems in hardware and correct the
problems before they cause several damages.
Insurance
A
means of protection from financial loss.
If
a computer is damaged or stolen or any kind of harm done then we can claim for
the insurance amount and get the economic support.
Dust Free Environment
Dust
particles can cause the failure of hardware components.
Computer
room should be absolutely free from dust and air pollution.
Protection from Fire
Due
to faulty wiring, loose connection, smoking in the computer room and overload
on power socket can cause fire in a room.
Using
fire alarms, fire doors, fire detectors and fire extinguishers can minimize the
damage of hardware components and loss of information from fire.
Protection from Theft
Use
of Lighting system, Grills on the windows, Safety Lock on the doors, Alarms,
CCTV (Closed Circuit Television) helps to protect from thieves.
Air Condition System
A
system for controlling the temperature and humidity (wetness) of the air
Maintains
suitable temperature or humidity in the computer room.
Room
Temperature should be maintained between 210C to 240C.
Power Protection Device
An
electric device that controls electric voltage and provides enough backup to
the computer system when there is power failure.
Computer
needs 220 volts to 240 volts constantly.
Some
common power protection devices are:
a)
UPS
b)
Volt
Guard
c)
CVT
d)
Stabilizer
e)
Spike
Guard
f)
Surge
Suppressor
Why Power Protection Device needed?
To
protect computer system from damage, expensive data loss and unnecessary down
time (is out of action or unavailable for use).
Volt Guard
A
power protection device that provides constant output voltage to the computer
system in case of high input voltage coming from the source.
UPS
UPS
is a battery supported power protection device which controls the electric
voltage and supplies clean and continuous power to the computer system even
during power failures.
The importance of UPS in computer security system is
that it controls fluctuation of electric voltage and provides enough backup
electric power to the computer system when there is power failure.
Spike Guard
A
device designed to protect electrical devices from voltage spikes.
Automatically maintains a constant voltage level.
Software security
The
security given to the software and data from being lost or damaged due to
accidental or intentional harm is called software security. Software prevents
the data loss by
Antivirus
software can detect and remove virus from the computer.
Scan
disk checks folders, bad sector and other error of the disk and fix them.
Software
for backup helps in securing the information by keeping backup.
Some of the software security measures
a)
keep
the backup copy of important data or software
b)
Scandisk
c)
Defragmentation
d)
use
Password
e)
use
antivirus software and update frequently
f)
use
firewall to prevent virus.
Scan disk
Scan
disk is a process which involves in maintaining the disk files and folders, bad
sectors, lost clusters, lost chains and other errors of the specific disk and
it can fix them if it is possible.
Full Forms:
CD – Compact Disk
DVD – Digital Versatile Disk
IoT – Internet of Things
PIN – Personal Identification Number
NAV – Norton Antivirus
AMC – Annual Maintenance Contract
UPS – Uninterruptible Power Supply
HTTP – Hyper Text Transfer Protocol
PC – Personal Computer
CPU – Central Processing Unit
"The more that you read, the more things you will know, the
more that you learn, the more places you’ll go.” —Dr. Seuss
