(1.3) Computer Security

 

(1.3) Computer Security

 

Computer Security / Cyber Security

Computer security refers to protecting computer and its content from damage, theft or misuse and action to prevent such incidents. Computer security includes security of data and information stored and being transferred, computer programs and applications and computer hardware.

 

Examples of computer security

Password, Biometric, Firewall, Cryptography etc

 

Types of computer security

Hardware security                   Software security.

 

Information Security (infosec)

Information security is the practice of preventing unauthorized access, use, disclosure, modification, 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.

 

We can protect our data by

·       by periodically checking the hard disk and replacing it if it shows failure symptoms

·       by copying the data in another disk in the system to avoid accidentally erasing or erasing data by unauthorized person.

·       we can copy important data into online storage devices which is also called cloud storage like Dropbox, Google Drive, iCloud, OneDrive etc.

·       We can also, sometimes, send important files as an attachment to our own mail such as Gmail or Hotmail.

·       Another issue of protecting data is preventing them from authorized access. Unauthorized users may access our data store in our computer in the cloud storage. To prevent our data from unauthorized access we have to protect the storage space, folder or file with password.

 

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

Phishing is the fake attempt to obtain sensitive information such as usernames, passwords and credit card details by disguising oneself as a trustworthy entity in an electronic communication.

 

A botnet is a logical collection of Internet-connected devices such as computers, smartphones or internet of things (IoT) devices whose security have been breached and control is given away to a third party.

 

A rootkit is a malicious code (kit) that hides in system area provides continued Administrator's (root) privileged access to a computer while actively hiding its presence.

 

Keylogger is hardware or software for recording the keys pressed on a keyboard secretly so that person using the keyboard does not know that their actions are being monitored.

 

Hacker

A computer hacker is any skilled computer expert who uses his/her technical knowledge to overcome a problem.

 

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. 

 

Types of malware

a)     A computer virus is a destructive program that copies itself and infects a PC, spreading from one file to another, and then from one PC to another when the files are copied or shared. . E.g. C-Brain, Frodo, Disk Killer, I Love You etc

Some viruses produce unnecessary messages on the screen, some virus hide files, some virus corrupt files and programs, some virus reduce memory size, etc.

Computer viruses can spread from one computer to other computers through sharing of infected portable disk like pendrive, opening a virus infected email, messages or attached files and downloading files and programs form the websites which are not secure.

b)     Computer worms use the network to send copies of themselves to other PCs, usually utilizing a security hole to travel from one host to the next, often automatically without user intervention.

c)     Trojan horses are applications that look like they are doing something harmless, but secretly have malicious code that does something else. 

d)     Spyware is any software installed on user’s  PC that collects your information without user’s knowledge

e)     Adware is a software application used by companies for marketing purposes; advertising banners are displayed while any program is running.

 

Any four symptoms of computer virus.

v Program takes long time to load.

v Increased use of disk space and growth in file size.

v Corrupting the system data.

v Renaming files with different names.

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

—  The process of identifying an individual usually based on a username and password is called an authentication system.

—  Authentication system makes sure that right people enters the system and access the right information.

—  Types of Authentication

Password              

Biometric

 

Password policy

A password policy defines the password strength rules that are used to determine whether a new password is valid.

 

Password

—  A password is a string of characters including letters, digits, or other symbols which confirms the identity of a user.

 

Importance of password protection

—  Password secures the data by protecting the data from unauthorized access.

—  We have to keep the password secure and strong so that unauthorized users may not gain access to the resource and misuse it with our identity.

 

Following are some of the tips to make password secure and strong:

l Never share your credentials online.

l Don't use easily guessable the name of a pet, child, family member, birthdays, birthplace, name of a favourite holiday.

l Don't use a sequence like abcd or 1234 which are, again, easily guessable.

l Mix characters, numbers and symbols. Also, mix small and capital letters.

l Avoid using the same password in all applications.

l Change password periodically

 

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.

·       E.g., fingerprints, facial patterns and voice.

 

Any four areas where biometric are used :

Mobile Device Security: secures smartphones and tablets, allowing access only to authorized users.

Cybersecurity: Prevent unauthorized access to sensitive data with multi-factor authentication.

Time and Attendance Tracking: track employee attendance accurately.

Financial Transactions: secure access to accounts and transactions.

 

Biometric verification

Biometric verification is a method of confirming an individual's identity by analyzing and measuring unique physical or behavioral characteristics like 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 on the basis of a set of user-defined rules. 

Firewall blocks unwanted traffic as well as malicious software from infecting your computer.

 

Its Types are:

- Network Firewall: A security system placed between a private internal network and the internet to monitor and control incoming and outgoing network traffic.

- Host-based Firewall: A software program installed on a single computer or device to monitor and control incoming and outgoing network traffic for that specific device.

 

Two uses of firewall

v Firewalls act as a barrier between an internal network and external networks (like the internet). By filtering traffic, they help safeguard sensitive data and critical resources within the network.

v Firewalls enforce access control policies by allowing or denying specific types of traffic based on criteria such as IP addresses, ports, protocols, and packet contents.

 

 

 

 Cryptography

—  Cryptography is the study of secure communications techniques that allow only the sender and intended recipient of a message to view its contents.

—  Cryptography is used to secure and protect data during communication.

 

Types of Cryptograpy

Encryption

Decryption

 

Encryption

—  Encryption is the technology to encode file or message that is being stored or transferred online in intelligible content which cannot be used by an unauthorized person.

—  Encryption is done by the person who is sending the data to the destination

—  Encryption helps in data protection by providing a secure way to store and transmit sensitive information.

 

Decryption

—  The conversion of encrypted data into its original form is decryption.

—  Decryption is done at the person who is receiving the data

 

Why data decryption is necessary?

To convert encrypted (coded) data into readable form.

 

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.

 

 

How antivirus helps to secure computer software?

An antivirus helps to secure computer software by detecting and removing malicious software, such as viruses, spyware, and Trojans, that can harm the computer or steal sensitive information.

 

Backup system

·       Backup 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.

 

Hardware Security

Hardware security is the protection given to the various hardware tools and equipment 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

The computer room should have physical security with proper locking system, controlled access of authorized persons only by having human guard or biometric machine.

 

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. Its role in computer security is to keep data and programs safe.

Computer needs 220 volts to 240 volts constantly.

Some common power protection devices are:

a)     UPS

b)     Volt Guard

c)     CVT (Constant Voltage Transformer)

d)     Spike Guard

e)     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 (Uninterruptible Power Supply)

·       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.

 

Why do you connect your PC to the UPS?

We connect PC to the UPS to control 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
Software security is the protection of computer systems and applications from threats, such as hacking, virus attacks, and unauthorized access, to ensure their confidentiality, integrity, and availability.

 

Some of the software security measures 

a)     Backup                 

b)     Scandisk              

c)     Password

d)     Antivirus

 

  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.

 

List some points about how we can protect our data.

Antivirus software can detect and remove virus from the computer.

Software for backup helps in securing the information by keeping backup

 

What is digital signature?

Digital signature is a security mechanism system used on the internet for data and information transaction by attaching a code at the end of the electronic message that confirms the authenticity of sent message.

 

What is digital currency?

Digital currency is a type of electronic money that is stored and exchanged using computers and other digital devices.