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

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

List the five modes of operation of a block cipher and explain any two in detail with diagrams.

Perform RSA encryption and decryption numerically given p=7, q=11, e=17 and plaintext m=8 (compute n, phi(n), d and ciphertext).

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

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

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 function and message schedule.

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.

Describe the differences between steganography and cryptography with examples.

Explain different types of DoS attack understanding tools like Jolt2, Bubonic.c, Land and LaTierra.

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

Write short notes on any two of the following: (i) Vulnerability Scanning Tools (ii) Spoofing tools like Arping (iii) Steganalysis tools / Stego detection (iv) IPSec AH and ESP.