Tutorial on Cryptography & Network Security

Tutorials on Cryptography & Network Security (IV IT)

Tutorial-I (30-07-2026):

1. Explain the Play Fair cipher algorithm? Encrypt the message ‘MY BALLOON’ using the key ‘MONARCHY.
2. Encrypt the message “this is an exercise” using Caesar Cipher with key = 20.  Ignore the space between words. 
3. Encrypt the message “the house is being sold tonight” using Vigenere cipher with key = “dollars”.  Ignore the space between words.
4. Use PlayFair cipher with keyword = “Health” to encipher the message “Life is Full of Surprises”
5. Use Hill Cipher to encipher the message “WE LIVE ON EARTH” using the key = “DCFH”

Tutorial-II (22-08-2026):

1. What is meant by Fabrication?  What are Confusion and Diffusion properties of Modern Ciphers?
2. What are the various modes of operations of Block Ciphers?  Explain Cipher Block Chaining Mode.  
3. Explain in detail Feistel Block Cipher structure with neat sketch.
4. With a neat diagram, explain one round of DES algorithm.
5. Discuss the key management techniques that can be used for sharing the private key securely in Symmetric Encryption.

Tutorial-III (02-09-2026):

1. Explain the key expansion function of AES algorithm. 
2. Discuss in detail the implementation of RSA Algorithm.
3. In the RSA system, the public key of a given user is e=31, n=3599 what is the private key of the user?  Also, critically analyze the security aspects of RSA.
4. How to use Chinese Remainder Theorem to reconstruct integers from their residues modulo functions.
5. Explain in detail about the implementation of Diffie-Hellman Key Exchange.

Tutorial-IV (19-09-2026):

1. Define Hash function. What are the requirements of Hash functions?  Explain.
2. Explain the basic working of a simple hash fuction like modular addition hash.  Give suitable example.
3. Name any two applications of Cryptographic Hash functions?  Explain them in detail.
4. Explain the Secure Hash algorithm with a neat sketch.  Compare SHA-2 and SHA-3 in terms of structure, security and performance.
5. Explain SHA-512 algorithm in detail using a block diagram.  Discuss the steps involved in message padding, message scheduling, and compression.

Tutorial-V (30-09-2026):

1. Define Smart Contract.  Explain the importance of Smart Contracts.
2. Briefly describe various Block Chain platforms available for application development using Block Chain technology.  
3. Explain in detail about Ethereum.
4. How does decentralization in Block Chain technology provide advantages over traditional centralized systems.  Explain.
5. Describe the Bitcoin protocol in detail.