1.3 Computer Security

 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