Communication and Computer Network Technologies [ Note of RBB (Rastriya Banijya Bank) ] | Note of Rastriya Banijya Bank

Network

·         A network is a collection of two or more computers and devices connected together.

·         It allows devices to communicate and exchange data.

·         Resources such as files, printers, software, and internet connections can be shared.

·         Networks improve communication, collaboration, and resource sharing.

·         Common types of networks include LAN (Local Area Network), MAN (Metropolitan Area Network), and WAN (Wide Area Network).

Communication

·         Communication is the process of exchanging information between two or more people or devices.

·         It involves a sender, a receiver, a message, and a communication medium.

·         Communication can be verbal, non-verbal, written, or electronic.

·         Effective communication ensures that information is delivered accurately and clearly.

·         In computer networks, communication enables devices to exchange data and share resources.

Elements of Communication

·         Sender is the person or device that sends the message.

·         Message is the information being communicated.

·         Medium/Channel is the path through which the message travels.

·         Receiver is the person or device that receives the message.

·         Feedback is the response given by the receiver after receiving the message.

Types of Communication

•         Verbal Communication uses spoken words to convey information.

•         Written Communication uses letters, emails, reports, and documents.

•         Non-verbal Communication uses gestures, facial expressions, and body language.

•         Electronic Communication uses digital devices and networks for communication.

Data Communication

•         Data communication is the process of exchanging data between two or more devices.

•         It allows computers and other devices to share information.

•         Data can include text, images, audio, video, and files.

•         Communication takes place through wired or wireless transmission media.

•         Data communication is essential for networking, internet access, and resource sharing.

Components of Data Communication

•         Sender is the device that sends the data.

•         Receiver is the device that receives the data.

•         Message is the data or information being transmitted.

•         Transmission Medium is the channel through which data travels.

•         Protocol is a set of rules that governs data communication.

Modes of Data Communication

A. Simplex Mode

       Simplex Mode allows data transmission in one direction only.

Features

1.      Data flows only from sender to receiver.

2.      No feedback possible.

3.      One device sends only.

Examples

·         Keyboard → Computer

·         Television broadcast

B. Half-Duplex Mode

      Half-Duplex Mode allows data transmission in both directions, but not at the same time.

Features

1.      Both devices can send and receive.

2.      Only one device communicates at a time.

3.      Communication is alternate.

Examples

·         Walkie-talkie

C. Full-Duplex Mode

      Full-Duplex Mode allows data transmission in both directions simultaneously..

Features

1.      Send and receive at the same time.

2.      Faster communication.

3.      Efficient use of network resources.

Examples

·         Telephone

·         Mobile phone

Networking Devices

·         Network devices are hardware components used to connect computers and other devices in a network.

·         They enable communication and the transfer of data between devices.

·         They help manage, control, and improve network performance.

·         Different network devices perform different functions, such as connecting, forwarding, and strengthening signals.

·         Common network devices include Repeater, Hub, Switch, Router, Bridge, Modem, and Gateway.

 

1. Repeater

·         A repeater is a networking device that regenerates and strengthens weak signals.

·         It extends the transmission distance of a network.

·         It operates at the Physical Layer (Layer 1) of the OSI model.

·         It does not filter or modify data.

·         Commonly used in large LANs and long-distance communication.

Function of Repeater

•         Regenerates weak or damaged network signals.

•         Extends the transmission distance of a network.

•         Improves signal strength and quality.

•         Helps reduce data loss during transmission.

•         Operates at the Physical Layer of the OSI model.

 

2. Hub

·         A hub is a basic networking device that connects multiple computers in a network.

·         It broadcasts data to all connected devices.

·         It operates at the Physical Layer (Layer 1) of the OSI model.

·         It does not identify the destination device.

·         Less efficient due to frequent data collisions.

Function of Hub

•         Connects multiple devices in a network.

•         Receives data from one device and broadcasts it to all devices.

•         Acts as a central connection point in a network.

•         Helps devices communicate within a LAN.

•         Operates at the Physical Layer of the OSI model.

 

3. Switch

·         A switch connects multiple devices within a LAN.

·         It sends data only to the intended destination device.

·         It operates at the Data Link Layer (Layer 2) of the OSI model.

·         It uses MAC addresses to forward data.

·         It reduces network traffic and improves performance.

Function of Switch

•         Connects multiple devices in a network.

•         Sends data only to the intended destination device.

•         Reduces network traffic and collisions.

•         Improves network performance and efficiency.

•         Operates at the Data Link Layer of the OSI model.

 

4. Router

·         A router connects two or more different networks.

·         It forwards data packets between networks using IP addresses.

·         It operates at the Network Layer (Layer 3) of the OSI model.

·         It allows multiple devices to share an internet connection.

·         Commonly used to connect a home or office network to the Internet.

Function of Router

•         Connects two or more different networks.

•         Routes data packets from source to destination.

•         Uses IP addresses to determine the best path.

•         Enables communication between networks and the Internet.

•         Improves network management and security.

 

1. Switching Technologies

·         Switching technology is the method of transferring data from a source to a destination in a network.

·         It helps data reach the correct destination efficiently.

·         It improves network performance and reduces congestion.

·         The three main types are Circuit Switching, Packet Switching, and Message Switching.

·         It is widely used in telephone and computer networks.

Types of Switching Technologies

1. Circuit Switching

·         Circuit Switching is a method in which a dedicated communication path is established between the sender and receiver before data transmission begins.

·         The connection remains active throughout the communication session.

·         Data follows the same fixed path from source to destination.

·         Once communication ends, the dedicated path is released.

·         Commonly used in traditional telephone systems.

 

Types of Circuit Switching

1. Space Division Switching

ü  A physical path is established between sender and receiver.

ü  Uses switches and crossbar connections.

ü  Each communication gets a dedicated path.

ü  Fast data transmission.

ü  Used in telephone exchanges.

2. Time Division Switching

ü  Multiple users share the same communication path.

ü  Each user is assigned a specific time slot.

ü  More efficient than space division switching.

ü  Reduces hardware requirements.

ü  Used in digital communication systems.

Characteristics of Circuit Switching

ü  Dedicated communication channel.

ü  Fixed route throughout communication.

ü  Continuous data transmission.

ü  Connection setup is required before communication.

ü  Resources remain reserved until communication ends.

Advantages of Circuit Switching

ü  Reliable communication.

ü  No packet loss during transmission.

ü  Constant bandwidth availability.

ü  Suitable for voice communication.

ü  Low transmission delay after connection establishment.

Disadvantages of Circuit Switching

ü  Wastes bandwidth when no data is transmitted.

ü  Expensive to maintain.

ü  Requires connection setup time.

ü  Less efficient for data communication.

ü  Network resources remain occupied.

Examples

• Landline telephone network.
• Traditional voice communication systems.

2. Packet Switching

·         Packet Switching is a technique in which data is divided into small units called packets before transmission.

·         Each packet contains source and destination address information.

·         Packets may travel through different routes in the network.

·         At the destination, packets are reassembled into the original message.

·         It is the most widely used switching technology in modern networks.

Types of Packet Switching

A. Datagram Packet Switching

ü  Each packet is treated independently.

ü   Packets may take different routes.

ü  Packets may arrive out of order.

ü  Used in the Internet (IP protocol).

B. Virtual Circuit Packet Switching

ü  A logical path is established before transmission.

ü  All packets follow the same route.

ü  Packets arrive in order.

ü  More reliable than datagram switching.

Characteristics of Packet Switching

ü  Data is divided into packets.

ü  No dedicated communication path.

ü  Packets travel independently.

ü  Efficient bandwidth utilization.

ü  Destination reassembles packets.

Advantages of Packet Switching

ü  Efficient use of bandwidth.

ü  Supports multiple users simultaneously.

ü  Faster and more economical.

ü  Reliable data transmission.

ü  Suitable for modern computer networks.

Disadvantages of Packet Switching

ü  Packets may arrive out of order.

ü  Possible packet loss during congestion.

ü  Requires packet reassembly.

ü  Delay may vary between packets.

ü  More complex than circuit switching.

Examples

ü  Internet communication.

ü  Email transmission.

ü  Video conferencing.

ü  Online gaming.

ü  Web browsing.

3. Message Switching

·         Message Switching is a technique in which the entire message is transmitted from one node to another.

·         No dedicated communication path is established.

·         Each intermediate node stores the complete message before forwarding it.

·         This method is known as Store-and-Forward Switching.

·         Suitable for non-real-time communication.

 

Types of Message Switching

1. Store-and-Forward Message Switching

ü  The entire message is stored at an intermediate node.

ü  The node forwards the message when the next link is available.

ü  No dedicated path is required.

ü  Reliable but slower communication.

ü  Used in telegraph and email systems.

2. Priority-Based Message Switching

ü  Messages are assigned different priorities.

ü  High-priority messages are transmitted first.

ü  Helps manage network traffic efficiently.

ü  Important messages experience less delay.

ü  Used in military and emergency communication systems.

Characteristics of Message Switching

ü  No dedicated path required.

ü  Entire message is stored at each node.

ü  Messages are forwarded when the next link becomes available.

ü  Transmission occurs in stages.

ü  Efficient use of network resources.

Advantages of Message Switching

ü  No need for dedicated circuits.

ü  Efficient utilization of network resources.

ü  Supports message prioritization.

ü  Reduces communication costs.

ü  Can handle large messages.

Disadvantages of Message Switching

ü  High transmission delay.

ü  Requires large storage at intermediate nodes.

ü  Not suitable for real-time communication.

ü  Processing overhead is high.

ü  Delivery time is unpredictable.

Examples

ü  Telegraph systems.

ü  Email systems (similar store-and-forward concept).

2. Modem

·         A modem (Modulator-Demodulator) is a device that connects a computer or network to the Internet.

·         It converts digital signals into analog signals and vice versa.

·         It enables data transmission over telephone lines, cable, or fiber networks.

·         It is commonly used for home and office Internet connections.

·         A modem works together with a router to provide Internet access to multiple devices.

Functions of Modem

ü  Converts digital signals into analog signals (Modulation).

ü  Converts analog signals into digital signals (Demodulation).

ü  Establishes Internet connectivity.

ü  Transmits and receives data between devices.

ü  Supports communication over telephone, cable, fiber, and wireless networks.

 

Types of Modem

1. Internal Modem

ü  Installed inside the computer system.

ü  Connected directly to the motherboard.

ü  Requires no external power supply.

ü  Less portable than external modems.

ü  Common in older desktop computers.

 

2. External Modem

ü  Connected outside the computer using USB or serial ports.

ü  Has its own power supply.

ü  Easy to install and maintain.

ü  Portable and flexible.

ü  Status indicators are visible.

 

3. Dial-Up Modem

ü  Uses telephone lines for communication.

ü  Establishes connection by dialing a telephone number.

ü  Very slow data transmission speed.

ü  Requires a dedicated telephone line during use.

ü  Mostly obsolete today.

 

4. DSL Modem (Digital Subscriber Line)

ü  Uses telephone lines for Internet access.

ü  Allows Internet and voice communication simultaneously.

ü  Faster than dial-up modems.

ü  Always-on Internet connection.

ü  Widely used in homes and offices.

 

5. Cable Modem

ü  Uses cable television networks.

ü  Provides high-speed Internet access.

ü  Faster than DSL in many cases.

ü  Suitable for multimedia applications.

ü  Common in urban areas.

 

6. Fiber Optic Modem (ONT)

ü  Uses fiber optic cables.

ü  Extremely high-speed Internet access.

ü  Supports long-distance communication.

ü  High reliability and performance.

ü  Used in modern broadband networks.

 

7. Wireless Modem

ü  Connects to the Internet using wireless technologies.

ü  Uses cellular networks such as 4G and 5G.

ü  Portable and convenient.

ü  No physical cable required.

ü  Suitable for mobile users.

 

3. Remote Network Access

·         Remote network access allows users to connect to a network from a different location.

·         It enables access to files, applications, and network resources over the Internet.

·         It supports remote work, online learning, and system administration.

·         A VPN (Virtual Private Network) is commonly used for secure remote access.

·         It provides flexibility while maintaining network security.

Functions of Remote Network Access

ü  Access files and applications remotely.

ü  Manage network resources from a distance.

ü  Provide remote technical support.

ü  Enable telecommuting and remote work.

ü  Facilitate secure communication.

 

Advantages of Remote Network Access

ü  Access resources from anywhere.

ü  Supports work-from-home environments.

ü  Reduces travel costs.

ü  Improves productivity.

ü  Enables quick technical support.

Disadvantages of Remote Network Access

ü  Security risks if not properly configured.

ü  Depends on Internet connectivity.

ü  Possible unauthorized access.

ü  Network latency may affect performance.

ü  Requires proper authentication mechanisms.

 

Types of Remote Network Access

1. Dial-Up Remote Access

ü  Uses telephone lines and modems.

ü  Requires dialing into a remote server.

ü  Slow and outdated technology.

ü  Suitable for basic communication.

ü  Rarely used today.

2. VPN (Virtual Private Network)

ü  Creates a secure connection over the Internet.

ü  Encrypts transmitted data.

ü  Protects user privacy and security.

ü  Commonly used by organizations.

ü  Supports secure remote work.

3. Remote Desktop Access

ü  Allows users to control a remote computer.

ü  Displays the remote computer's screen locally.

ü  Supports file transfer and application access.

ü  Used by system administrators and support staff.

ü  Example: Remote Desktop Protocol (RDP).

4. Cloud-Based Remote Access

ü  Accesses resources hosted in cloud environments.

ü  Requires an Internet connection.

ü  Scalable and flexible.

ü  Supports collaboration.

ü  Used by modern organizations.

 

 

4. Error Detection and Correction Techniques

·         Error detection and correction techniques ensure accurate data transmission over a network.

·         They detect and correct errors caused by noise or transmission problems.

·         Common error detection methods include Parity Check, Checksum, and Cyclic Redundancy Check (CRC).

·         Common error correction methods include Hamming Code and Forward Error Correction (FEC).

·         These techniques improve data reliability and communication accuracy.

Error Detection Techniques

ü  Error detection is the process of identifying whether transmitted data contains errors.

ü  It helps the receiver determine if the received data is correct.

ü  If an error is detected, retransmission may be requested.

1. Parity Check

ü  Parity Check is the simplest error detection technique.

ü  An extra bit called the parity bit is added to the data.

Types of Parity

A. Even Parity

ü  Total number of 1's (including parity bit) must be even.

ü  If the number of 1's is odd, parity bit = 1.

ü  Used to detect single-bit errors.

B. Odd Parity

ü  Total number of 1's (including parity bit) must be odd.

ü  If the number of 1's is even, parity bit = 1.

ü  Also used for single-bit error detection.

Advantages

ü  Simple and easy to implement.

ü  Low overhead.

ü  Fast error detection.

Disadvantages

ü  Cannot detect all errors.

ü  Cannot correct errors.

ü  Ineffective for multiple-bit errors.

2. Checksum

ü  Checksum is an error detection method in which data blocks are added together.

ü  The resulting value is sent along with the data.

 

Working

ü  Sender calculates checksum.

ü  Receiver recalculates checksum.

ü  Values are compared.

ü  Mismatch indicates an error.

Advantages

ü  Simple implementation.

ü  Detects many transmission errors.

ü  Widely used in networking.

Disadvantages

ü  Cannot correct errors.

ü  Less reliable than CRC.

Applications

ü  TCP/IP protocols.

ü  Network communication.

3. Cyclic Redundancy Check (CRC)

ü  CRC is a powerful error detection technique using polynomial division.

ü  Extra bits called CRC bits are added to the message.

Working

ü  Sender generates CRC value.

ü  Receiver performs the same calculation.

ü  Different results indicate errors.

Advantages

ü  Highly accurate.

ü  Detects burst errors.

ü  Widely used in communication systems.

Disadvantages

ü  More complex than parity checks.

ü  Cannot correct errors by itself.

Applications

ü  Ethernet networks.

ü  Data storage devices.

ü  Wireless communication.

Error Correction Techniques

•         Error correction is the process of detecting and correcting errors without retransmission.

•         It improves communication reliability.

1. Hamming Code

ü  Hamming Code is an error correction technique developed by Richard Hamming.

ü  It can detect and correct single-bit errors.

Characteristics

ü  Uses parity bits at specific positions.

ü  Identifies the exact location of an error.

ü  Automatically corrects single-bit errors.

Advantages

ü  Detects and corrects errors.

ü  Improves data reliability.

ü  Efficient for memory systems.

Disadvantages

ü  Additional parity bits required.

ü  More complex than simple parity checks.

Applications

ü  Computer memory systems.

ü  Digital communication systems.

2. Forward Error Correction (FEC)

ü  FEC adds redundant data to transmitted information.

ü  Receiver can detect and correct errors without retransmission.

Characteristics

ü  No need for retransmission.

ü  Suitable for real-time communication.

ü  Improves communication reliability.

Advantages

ü  Fast error correction.

ü  Suitable for satellite and wireless communication.

ü  Reduces retransmission delays.

Disadvantages

ü  Increases bandwidth usage.

ü  More processing required.

Applications

ü  Satellite communication.

ü  Mobile networks.

ü  Digital television.

3. Automatic Repeat Request (ARQ)

ü  ARQ is an error control technique that combines error detection and retransmission.

ü  If an error is detected, the receiver requests retransmission.

Types of ARQ

A. Stop-and-Wait ARQ

ü  Sender waits for acknowledgment after each frame.

ü  Simple implementation.

ü  Low efficiency.

B. Go-Back-N ARQ

ü  Multiple frames can be sent before acknowledgment.

ü  If an error occurs, retransmits the erroneous frame and all following frames.

C. Selective Repeat ARQ

ü  Only erroneous frames are retransmitted.

ü  More efficient than Go-Back-N.

Advantages

ü  High reliability.

ü  Accurate data delivery.

ü  Efficient error recovery.

Disadvantages

ü  Requires retransmission.

ü  Additional network traffic.

 

Internet Services

·         Internet services are facilities provided through the Internet for communication, information sharing, and online activities.

·         They allow users to access various resources and applications worldwide.

·         Common Internet services include Email, Web Browsing, File Transfer, Online Banking, Video Conferencing, and Social Networking.

·         They provide fast and convenient ways to exchange information and use online resources.

·         Internet services are widely used in education, business, entertainment, and communication.

Common Internet Services

·         Email (Electronic Mail):

o    Allows users to send and receive electronic messages over the Internet.

o    Supports file attachments such as documents, images, and videos.

·         Web Browsing (World Wide Web):

o    Allows users to access websites and web pages using web browsers.

o    Provides information through text, images, videos, and online resources.

·         File Transfer Service:

o    Enables users to upload and download files through the Internet.

o    Used for sharing documents, software, and other digital files.

·         Online Communication:

o    Provides instant communication through text messages, voice calls, and video calls.

o    Examples include messaging apps and video meeting platforms.

·         Video Conferencing:

o    Allows people to conduct online meetings, classes, and discussions through audio and video.

o    Helps in remote work and online education.

·         Social Networking:

o    Allows users to connect, communicate, and share content with others.

o    Helps build online communities and professional networks.

·         Online Banking:

o    Allows users to perform banking activities through the Internet.

o    Includes money transfer, bill payment, and account management.

·         E-Commerce:

o    Enables buying and selling of goods and services online.

o    Provides online shopping, digital payments, and home delivery services.

·         Cloud Services:

o    Provides online storage and access to applications through the Internet.

o    Allows users to store, share, and manage data from anywhere.

·         Online Education:

o    Provides digital learning resources, virtual classes, and online courses.

o    Helps students and teachers access educational materials easily.

·         Entertainment Services:

o    Provides online access to movies, music, games, and digital content.

o    Allows users to enjoy entertainment anytime and anywhere.

 

Internet Protocol / Addressing

·         Internet Protocol (IP) is a set of rules used for sending and receiving data over the Internet.

·         It provides a unique address to each device connected to a network.

·         An IP address identifies the source and destination of data communication.

·         The two main versions of IP are IPv4 (32-bit address) and IPv6 (128-bit address).

·         IP addressing enables proper routing and communication between devices on the Internet.

·         The Two main version of IPare:

IPv4 (32-bit Address)

·         IPv4 (Internet Protocol Version 4) is the fourth version of the Internet Protocol.

·         It uses a 32-bit address to identify devices on a network.

·         It provides approximately 4.3 billion unique IP addresses.

·         IPv4 addresses are written in decimal format, such as 192.168.1.1.

·         It is the most widely used IP addressing system.

 

IPv6 (128-bit Address)

·         IPv6 (Internet Protocol Version 6) is the latest version of the Internet Protocol.

·         It uses a 128-bit address to identify devices on a network.

·         It provides a much larger number of IP addresses compared to IPv4.

·         IPv6 addresses are written in hexadecimal format, such as 2001:0db8:85a3::8a2e:0370:7334.

·         It provides better security, efficiency, and support for the growing number of Internet-connected devices.

Network Security

·         Network security is the practice of protecting computer networks and data from unauthorized access, attacks, and damage.

·         It ensures the confidentiality, integrity, and availability of network resources.

·         It prevents threats such as viruses, malware, hacking, and data theft.

·         Security methods include firewalls, antivirus software, encryption, and access control.

·         It helps maintain safe and reliable communication over networks.

Security Methods

1. Firewall:

·         A firewall is a network security system that monitors and controls incoming and outgoing network traffic.

·         It works as a barrier between a trusted internal network and an untrusted external network.

·         It blocks unauthorized access and prevents harmful traffic from entering the network.

·         Firewalls can be hardware-based, software-based, or cloud-based.

2. Antivirus:

·         Antivirus software protects systems from malicious programs such as viruses, worms, trojans, and spyware.

·         It scans files, applications, and network traffic to detect and remove threats.

·         It helps prevent data loss and system damage caused by malware attacks.

3. Encryption:

·         Encryption converts readable data into an unreadable format called ciphertext.

·         Only authorized users with the correct key can decrypt and access the original information.

·         It protects sensitive data during storage and transmission.

·         It is commonly used in online banking, secure websites, and private communication.

4. Access Control:

·         Access control manages who can access network resources and what actions they can perform.

·         It uses usernames, passwords, permissions, and security policies.

·         It prevents unauthorized users from accessing confidential information.

5. Authentication:

·         Authentication verifies the identity of users before allowing them to access a network.

·         It may use passwords, security tokens, fingerprints, facial recognition, or multi-factor authentication.

·         It helps prevent unauthorized account access.

6. Virtual Private Network (VPN):

·         A VPN creates a secure and encrypted connection between a user and a network over the Internet.

·         It protects data from being intercepted during online communication.

·         It is commonly used by remote workers and organizations to access private networks securely.

7. Intrusion Detection System (IDS):

·         IDS is a security system that monitors network activities for suspicious behavior.

·         It detects possible attacks and sends alerts to network administrators.

·         It helps identify threats before they cause serious damage.

 

8. Intrusion Prevention System (IPS):

·         IPS monitors network traffic and automatically blocks detected threats.

·         It prevents malware, unauthorized access, and cyber attacks in real time.

·         It works together with firewalls and other security tools.

Importance of Network Security

• Protects important data from theft and unauthorized access.
• Prevents cyber attacks and network damage.
• Ensures safe communication between devices.
• Maintains privacy and confidentiality of information.
• Helps organizations securely use Internet and network services.

 

Cryptography

·         Cryptography is the technique of protecting information by converting data into a secure format.

·         It uses mathematical algorithms to encrypt and decrypt data.

·         It ensures data confidentiality, integrity, authentication, and security.

·         Encryption converts plain text into unreadable ciphertext, while decryption converts it back into readable data.

·         Common types of cryptography include Symmetric Key Cryptography and Asymmetric Key Cryptography.

 

Common Types of Cryptography

1. Symmetric Key Cryptography

·         Uses the same key for both encryption and decryption.

·         The sender and receiver must share the same secret key.

·         It is faster and suitable for encrypting large amounts of data.

·         Common algorithms include AES (Advanced Encryption Standard) and DES (Data Encryption Standard).

2. Asymmetric Key Cryptography

·         Uses two different keys: a public key and a private key.

·         The public key is used for encryption, and the private key is used for decryption.

·         It provides better security for data exchange over networks.

·         Common algorithms include RSA and ECC (Elliptic Curve Cryptography).

 

Components of Cryptography

• Plaintext:
• The original message or data that needs to be protected.
• Example: A password, document, or message.
• Encryption:
• The process of converting plaintext into unreadable ciphertext.
• It protects data from unauthorized users.
• Ciphertext:
• The encrypted form of data that cannot be understood without a key.
• It helps keep information secure during transmission.
• Decryption:
• The process of converting ciphertext back into its original plaintext form.
• It allows authorized users to access the information.
• Key:
• A secret value used by encryption and decryption algorithms.
• It controls the conversion of data between plaintext and ciphertext.

Applications of Cryptography

·         Protecting online transactions and banking information.

·         Securing passwords and user accounts.

·         Encrypting emails and private messages.

·         Protecting data stored on computers and cloud systems.

·         Providing secure communication over the Internet.

·         Creating digital signatures for authentication.

Importance of Cryptography

·         Protects confidential information from unauthorized access.

·         Ensures data integrity by preventing unwanted changes.

·         Provides secure communication between users and systems.

·         Helps verify the identity of users and organizations.

·         Protects sensitive information from cyber threats.