Assignment Code: MSEI-023/TMA/2022

Course Code: MSEI-023

Assignment Name: Cyber Security

Year: 2022-2023

Verification Status: Verified by Professor

There are three questions in this assignment. Answer all the questions. You may use illustrations and diagrams to enhance your explanations.

Q1) Explain the role of Certificate Authority in transmitting digital information through the mechanism of cryptography?

Ans) A Certificate Authority plays a critical role in the transmission of digital information through the mechanism of cryptography. Cryptography involves the use of encryption to protect data from unauthorized access or manipulation, and digital certificates are used to verify the authenticity of the communicating parties.

A Certificate Authority is an organization that issues digital certificates to individuals, organizations, and devices that want to communicate securely over the internet. When a user requests a digital certificate from a CA, the CA verifies the user's identity, and then issues a unique digital certificate containing the user's public key, as well as other information about the user and the issuing CA.

When two parties communicate using encryption, they use each other's public keys to encrypt and decrypt the data. However, in order to trust that the public key belongs to the intended recipient, the recipient's public key must be verified as legitimate. This is where the digital certificate issued by a trusted Certificate Authority comes in.

When the recipient presents their digital certificate, the sender can verify that the certificate was issued by a trusted CA, and that the public key contained in the certificate is indeed associated with the intended recipient. This helps to ensure that the communication is secure and that the information being transmitted cannot be intercepted or modified by unauthorized parties.

In summary, the role of a Certificate Authority in transmitting digital information through the mechanism of cryptography is to issue digital certificates that verify the identities of communicating parties and to ensure that the public keys used for encryption and decryption are legitimate and trusted.

Q2) Explain the functions and type of firewalls?

Ans) A firewall is a network security device that monitors and controls incoming and outgoing network traffic based on an organization's previously established security policies. It acts as a barrier between a private internal network and the public internet, allowing only authorized traffic to enter or leave the network. Firewalls help protect against unauthorized access, data breaches, and cyber-attacks.

The functions of a firewall include:

1. Packet Filtering: Examines each packet of data that passes through the firewall and decides whether to allow or block it based on pre-defined rules.

2. Network Address Translation (NAT): Hides the IP addresses of devices on a private network by replacing them with a single public IP address, thereby providing an additional layer of security.

3. Application-Level Gateway (Proxy): Acts as an intermediary between the client and server to protect the network by examining application-layer data packets.

4. Stateful Inspection: Monitors incoming and outgoing network traffic and verifies that the packets belong to a valid connection. It can help prevent attacks like DoS attacks.

There are three main types of firewalls:

1. Packet Filtering Firewall: Examines each packet of data that passes through the firewall and decides whether to allow or block it based on pre-defined rules.

2. Stateful Inspection Firewall: Monitors incoming and outgoing network traffic and verifies that the packets belong to a valid connection.

3. Application-Level Gateway (Proxy) Firewall: Acts as an intermediary between the client and server to protect the network by examining application-layer data packets.

Q3) What is web architecture? Explain the role of IETF, IAB and IESG in governing Web Architecture.

Ans) Web architecture refers to the fundamental principles, protocols, and technologies that underlie the operation and evolution of the World Wide Web. It encompasses all aspects of the web, including its design, infrastructure, standards, and governance.

The Internet Engineering Task Force (IETF), Internet Architecture Board (IAB), and Internet Engineering Steering Group (IESG) are key organizations that play an important role in governing web architecture. Here's how each of these organizations contribute:

1. Internet Engineering Task Force (IETF): The IETF is a community-driven organization responsible for developing and promoting internet standards, including web protocols. IETF creates and maintains the technical standards and specifications for the web, such as HTTP, HTML, and DNS. They also establish working groups to address specific technical issues, develop new technologies, and propose updates to existing standards.

2. Internet Architecture Board (IAB): The IAB provides oversight and guidance for the technical evolution of the internet, including the World Wide Web. It reviews and approves the technical work done by the IETF and other technical groups, ensuring that all new protocols and technologies adhere to established technical principles and design goals. The IAB also identifies emerging technical trends, challenges, and issues and provides guidance on how to address them.

3. Internet Engineering Steering Group (IESG): The IESG is responsible for the day-to-day management of IETF activities. It provides technical and organizational leadership for the IETF and makes final decisions on the adoption of new protocols and standards. The IESG ensures that new standards meet the technical requirements, design principles, and goals of the IETF and IAB.

In summary, the IETF, IAB, and IESG play critical roles in governing web architecture by creating and maintaining technical standards and specifications, overseeing the evolution of the internet and web, and providing guidance on technical issues and trends. Through their collective efforts, these organizations help ensure the stability, reliability, and security of the web, making it accessible and useful to people all around the world.