Cryptography & Information Security (CS-703 (A)) - Important Questions

Explain the DES algorithm including key generation, encryption and decryption with diagram and role of S-boxes

Explain the concept of modular arithmetic with suitable examples. Derive Euler's theorem and state its significance in cryptography.

Encrypt the following using play fair cipher using the keyword MONARCHY. Use X for blank spaces "SWARAJ IS MY BIRTH RIGHT".

Find the multiplicative inverse of $11 \bmod 26$ using the Extended Euclidean Algorithm and verify your answer.

Compare Classical Cryptosystems such as Caesar Cipher and Playfair cipher. Perform frequency analysis on a simple ciphertext example.

To find :

List the five modes of operation of a block cipher and explain any two.

Explain Fermat's little theorem with an example.

Write short notes on any Two:

Define cryptanalysis and explain cryptanalysis of a substitution cipher.

Explain the concept of cryptanalysis and brute force attack.

Explain how Cipher Feedback (CFB) mode converts a block cipher into a stream cipher.

Perform RSA encryption and decryption numerically given $p, q, e$ and plaintext $m$ (compute $n, \phi(n), d$ and ciphertext).

Explain the Diffie-Hellman key exchange algorithm for establishing a shared secret, including Computational and Decisional Diffie-Hellman problems

Compute public values $Y_A, Y_B$ and shared secret key $K$ using Diffie-Hellman algorithm given prime $q$, primitive root $\alpha$, and private keys $X_A, X_B$

Explain the structure of AES including key expansion and round transformation steps for encryption and decryption.

Explain the RSA algorithm including encryption and decryption with a suitable example.

Describe the Schnorr Identification Scheme in detail.

State/explain the Chinese Remainder Theorem and find $X$ satisfying the given system of congruences using CRT.

What is a digital signature and explain the Digital Signature Standard (DSS) including signature generation and verification with block diagram.

Explain the Kerberos authentication system with diagram and the roles of its different servers (AS, TGS, etc.).

Explain the steps involved in the SHA-512 algorithm to produce a 512-bit message digest, including compression and order of finding a collision.

Define Hash Function. Differentiate between MD5 and SHA algorithms with suitable examples.

Explain the role of the Ticket Granting Server (TGS) in inter-realm Kerberos operations.

What are the types of attacks addressed by message authentication? What are the two levels of functionality the comprise a message authentication or digital signature mechanism?

Explain in short different method of distribution of public key management.

What is MD5? Explain MD5 with neat and clean diagram.

Explain the Secure Hash Algorithm (SHA) with its merits and demerits.

Define firewall and explain its types/design and its role/use in network security architecture.

Discuss Encapsulating Security Payload (ESP) and explain how ESP is applied in transport mode and tunnel mode.

Discuss Email Security services and explain the working of Pretty Good Privacy (PGP) and S/MIME.

Draw the IP security authentication header and describe the function of each field.

Explain the IPSec AH and ESP protocols and how they are used for secure data transmission.

What is a firewall? Explain the different types of firewalls.

Explain the usage of session keys, public keys and private keys in PGP.

Analyze the Cryptographic algorithms used in S-MIME. Explain S-MIME certification processing.

Explain the SSL Handshake Protocol and the sequence of steps for establishing a new session, with diagram.

Explain why PGP compresses the message and why compression is applied after signing but before encryption.

What is a Honeypot? Explain types of honeypot.

Write short notes on spoofing tools, ECC, firewalls and cryptanalysis (any three)

Write short notes on any two of the following:

Describe the differences between steganography and cryptography with examples.

What is steganography and explain two tools used for hiding information in digital media.

Write short notes on Vulnerability Scanning Tools and DoS Attack Understanding Tools with examples.

Explain different types of DoS attack understanding tools.

What is steganography and explain different types of steganography.

Explain in short different types of Trojans detection tools.