Assignment Code: MSEI-022/TMA/2022

Course Code: MSEI-022

Assignment Name: Network Security

Year: 2022

Verification Status: Verified by Professor

There are two questions in this assignment. Answer all the questions.

Q1) (a) Explain Masquerade.

Ans) Masquerade is a type of attack where an attacker impersonates another user, system, or device to gain unauthorized access to sensitive information or systems. This can be achieved through a variety of methods, such as spoofing IP addresses, falsifying login credentials, or using stolen identity information. Masquerade attacks can have serious consequences for organizations, as they can result in the loss of sensitive information, financial loss, and damage to reputation. To prevent masquerade attacks, organizations should implement strong authentication measures and monitor their systems for unusual or suspicious activity.

Q1) (b) Explain Shared Key cryptography.

Ans) Shared Key cryptography, also known as symmetric-key cryptography, is a method of encrypting data where the same secret key is used to both encrypt and decrypt the data. The key is shared between the sender and the recipient and must be kept confidential to ensure the security of the encrypted data. Examples of symmetric key algorithms include AES, DES, and Blowfish. While shared key cryptography is fast and efficient, it has the disadvantage of requiring both the sender and the recipient to securely share the same key, which can be a challenge in large or complex systems.

Q1) (c) Explain Attacks on Digital Watermark.

Ans) Attacks on digital watermarks are methods used to remove or alter a digital watermark, a type of digital signature used to identify the ownership or origin of a digital work. There are several types of attacks on digital watermarks, including removal attacks, modification attacks, and collision attacks. These attacks can be carried out through a variety of methods, including cropping, resizing, filtering, and adding noise. Protecting digital watermarks against these attacks is important to ensure the authenticity and integrity of digital works and can be done using robust watermarking algorithms and secure embedding methods.

Q1) (d) Explain Biometrics.

Ans) Biometrics is the science of identifying individuals based on their unique biological characteristics, such as fingerprints, facial features, voice patterns, and iris scans. These traits are used for secure authentication and to grant access to physical and digital systems.

Q1) (e) Explain Piracy-Driven Networks.

Ans) Piracy-driven networks, also known as peer-to-peer networks, are online systems that allow users to share files directly with each other. These networks are often used to share copyrighted materials, such as movies, music, and software, without permission from the copyright holders. In a piracy-driven network, users download and upload files directly to and from each other's computers, rather than from a centralized server. This means that there is no single point of control or ownership over the files being shared. Instead, the network is driven by the collective actions of its users.

Q2) (i) Explain the difference between Transport mode and Tunnel mode.

Ans) Transport mode and Tunnel mode are two ways of encapsulating data for secure transmission in a virtual private network (VPN). The main difference between them lies in how they protect the data being transmitted and where they apply encryption and authentication. Transport mode is used to protect data that is sent between two endpoints within the same network. In this mode, only the payload or the data itself is encrypted while the IP header is left unencrypted. The source and destination IP addresses remain visible in the header. Transport mode is commonly used when both endpoints are trusted, and the focus is on protecting the data.

Tunnel mode is used to protect data that is sent across an untrusted network, such as the internet. In this mode, the entire original IP packet, including the header and the payload, is encrypted, and encapsulated within a new IP packet. The new IP header contains different source and destination IP addresses, so that the original addresses are not visible to the network through which the data is transmitted. Tunnel mode is commonly used to create a secure connection between two networks or to connect a remote user to a network.

Q2) (ii) Explain the difference between Human aided networks and Packet based networks.

Ans) Human-aided networks and packet-based networks are two different types of communication networks. A human-aided network is a type of network in which humans are involved in the routing and processing of messages. For example, a courier network that relies on human couriers to physically deliver messages from one location to another is a human-aided network. Another example is a social network, where users communicate with each other through social media platforms, chat, or email. In a human-aided network, humans play an active role in transmitting and processing information.

The main difference between human-aided and packet-based networks is the level of automation in the transmission and processing of information. In a human-aided network, humans are actively involved in the transmission and routing of information, whereas in a packet-based network, the transmission and routing are automated and done through the protocol stack. Additionally, human-aided networks are typically slower and less efficient than packet-based networks because they rely on human intervention and are subject to human error, while packet-based networks can transmit data more quickly and with a higher level of accuracy due to their automated nature.

Q2) (iii) Explain the difference between Application security and data security.

Ans) Application security and data security are two different aspects of overall information security.

Application security is focused on protecting software applications and systems from unauthorized access, use, or modification. This includes protecting against threats such as hacking, malware, and other types of cyberattacks. Application security measures include techniques like authentication, access control, encryption, firewalls, and other security mechanisms to protect the application and the underlying infrastructure. The goal of application security is to prevent attackers from exploiting vulnerabilities in the application or system, and to ensure that the application functions correctly and securely. Data security, on the other hand, is focused on protecting the data that is stored, transmitted, or processed by an application or system. This includes protecting data from theft, loss, unauthorized access, modification, or destruction. Data security measures include techniques like encryption, access control, backups, and disaster recovery to ensure that the data is protected from unauthorized access and that it remains available even in the event of a security breach. The goal of data security is to protect the confidentiality, integrity, and availability of data.

Q2) (iv) Explain the difference between HTTPS and HTTP.

Ans) HTTP (Hypertext Transfer Protocol) and HTTPS (Hypertext Transfer Protocol Secure) are both protocols used to transfer data over the internet. However, they differ in the level of security they provide. HTTP is a protocol used to transfer data between a client and a server. It is an application layer protocol that is used for the transmission of data, including web pages, images, videos, and other types of content. However, HTTP is not a secure protocol and does not provide any encryption or protection for the data being transferred. This means that any data sent over HTTP can be intercepted and read by anyone who has access to the network, including hackers and other malicious actors. The main difference between HTTP and HTTPS is that HTTPS uses encryption to protect the data being transmitted, while HTTP does not. When a user connects to a website using HTTPS, the connection is secured with a digital certificate, which verifies the authenticity of the website and ensures that the data being transmitted is encrypted and protected.

Q2) (v) Explain the difference between Symmetric cryptography and Asymmetric cryptography.

Ans) Symmetric cryptography, also known as secret-key cryptography, is a type of encryption that uses the same key for both encryption and decryption of data. The key is a shared secret between the sender and receiver, and it must be kept secret to ensure the security of the encrypted data. The most commonly used symmetric encryption algorithm is the Advanced Encryption Standard. Symmetric cryptography is fast and efficient, making it a popular choice for encrypting large amounts of data. Asymmetric cryptography, also known as public-key cryptography, is a type of encryption that uses two different keys for encryption and decryption. The public key is freely available to anyone who wants to send encrypted data to the owner of the key, while the private key is kept secret by the key owner and is used to decrypt the data. Asymmetric cryptography is based on complex mathematical algorithms and is slower than symmetric cryptography, but it is more secure because the private key is never transmitted over the internet.