Cryptography and Network security — Winter 2025

Define Cryptography and Cryptanalysis. Draw conventional cryptosystem.

List and explain various types of attacks on encrypted message.

Explain single round function of DES with suitable diagram.

Differentiate Symmetric and Asymmetric key cryptography.

Use playfair algorithm with key “monarchy” and encrypt the text “crypt tool”.

Explain various steps of AES with diagram.

Which security goal is achieved with SHA-1 algorithm? Explain steps of SHA-1.

Explain rail fence Cipher technique

Explain the terms diffusion and confusion.

Explain NIST digital Signature algorithm

Differentiate session key and master key.

Explain different characteristics of hash function.

List various modes of operations in block cipher encryption and explain any two.

Explain Euler’s totient function with example.

Pand Qare two prime numbers. P=7, and Q=17. Take public key E=5. If plain text value is 6, then what will be cipher text value according to RSA algorithm?

What is a nonce? Explain the key distribution scenario if Awishes to establish logical connection with B (Aand Bboth have a master key shared with KDC).

Discuss the triple DES scheme with two keys and its limitations.

Explain Encryption and decryption in RSA algorithm.

Explain Deffie Hellman key exchange scheme in detail.

Write the elements of X.509 certificates.

What steps sending PGP(pretty good privacy) perform?

Explain Kerberos in detail.

Describe various ways to distribute public key in public key cryptography.

Explain the secure socket layer handshake protocol action.

How encapsulating security payload help in IP security? Explain various fields in Encapsulating security payload packet.