Assignment on Cryptography & Network Security

 

Assignment-1 Questions

SET-1:

1. Briefly define the monoalphabetic cipher. What is the difference between a monoalphabetic cipher and a polyalphabetic cipher?
2. Explain the Play Fair cipher algorithm? Encrypt the message ‘MY BALLOON’ using the key ‘MONACHRY’
3. Discuss any four Substitution Technique and list their merits and demerits.
4. Explain the DES algorithm with neat sketch.
5. Explain about Hill Cipher. Consider the plaintext "paymoremoney" and use the encryption key: K=

Find the cipher text.

SET-2:

1. Define Steganography and Hash function.
2. Write notes on two basic functions used in encryption algorithms?  Also differentiate between public key and private key.
3. Identify the attacks on block ciphers.  Also define Group and Ring in block ciphers.
4. What do you mean by Substitute byte transformation in AES?  Which four tasks are performed in each round of AES Cipher?
5. How to use Chinese Remainder Theorem to reconstruct integers from their residues modulo functions.

SET-3:

1. Explain the followings: (a) Playfair cipher  (b) Vernam cipher
2. Explain the basic principle of rotor machine.
3. Explain in Detail about DES Algorithm
4. What are the design parameters of Feistel cipher network?
5. Write the difference between ECB and CBC with neat diagram

SET-4:

1. Explain the importance of cryptography in the evolution of secure communication with suitable historical examples.
2. Differentiate between substitution and transposition techniques in classical cryptography.  What is the main difference between a stream cipher and a block cipher?
3. What is steganography? How does it differ from cryptography? Explain.
4. Explain in detail about AES algorithm
5. Explain about Chinese Remainder theorem.

SET-5:

1. Explain the working principle of the Caesar cipher. Encrypt the text "NETWORK" using a key value of 3.
2. Explain the work of a Rotor Machine with a simple example. Show how a single plaintext letter is transformed through multiple rotors into ciphertext.
3. Describe the working of a Columnar Transposition Cipher by encrypting the message “CRYPTOGRAPHY IS FUN” using the keyword “NETWORK.” Show column arrangement, transposition steps, and final ciphertext.
4. Explain the key expansion round key generation logic used in DES. How do round keys enhance security?
5. Explain the structure and working of the Advanced Encryption Standard (AES). Include key sizes, block size, and the role of Sub-Bytes, Shift-Rows, Mix-Columns, and Add-Round-Key operations.

SET-6:

1. Compare and Contrast stream ciphers and block ciphers.
2. Briefly explain the design principles of block cipher.
3. What is the block size used in the Advanced Encryption Standard (AES)?  Also state few applications of the Chinese Remainder Theorem (CRT) in cryptography.
4. Describe common attacks on block ciphers like brute-force, differential, linear cryptanalysis. Explain how block cipher design principles help resist these attacks.
5. Explain the Chinese Remainder Theorem (CRT) with a numerical example. Solve for x in the system: x ≡ 1 (mod 3), x ≡ 2 (mod 4), x ≡ 3 (mod 5).

Assignment-2 Questions

SET-1:

1. Explain in detail Hash Functions.
2. Describe SHA-1 algorithm in detail.
3. Describe MD5 algorithm in detail.
4. Define Block Chain.  What is the role of Smart Contracts in Block Chain technology.
5. Explain the importance of Block Chain technology in Supply Chain Management.

SET-2:

1. Write the difference between public key and private key.  Also explain RSA algorithm in detail.
2. How man in middle attack can be performed in Diffie Hellman algorithm.
3. What are the requirements of hash functions? Explain.  
4. Explain any Applications of Cryptographic Hash Functions in detail.
5. What is blockchain?  What is the role of smart contract in Block Chain technology?

SET-3:

1. Write the difference between public key and private key.  Also explain RSA algorithm in detail.
2. Derive a birthday attack on a simplified hash function H(x) = (sum of letters mod 10) using two different messages.
3. Describe and compare the blockchain development platforms such as Ethereum, Hyperledger and Corda.
4. Discuss the key features of Bitcoin. Explain how transactions are validated and how miners earn rewards.
5. Analyze the advantages and limitations of blockchain applications in finance, and healthcare sectors.

SET-4:

1. What are the principles of public key cryptosystems?  List the 6 ingredients of public key encryption.
2. What are the various approaches to Public-key Management? Explain about the RSA algorithm with example as P=11, q=5, e=3 M=5, d=?
3. How to establish a shared secret between two parties using Diffie-Hellmann key exchange algorithm? Explain.
4. Define hash function.  What is the role of hash functions in providing security.
5. Discuss about Message Authentication and how authentication of messages can be done securely using Digital Signatures.

SET-5:

1. Explain RSA algorithm with suitable steps. Let p= 17, q=11, e=7 and d=23. Calculate the public key & private key and show encryption and decryption for plain text M= 77 by using RSA algorithm.
2. Define Public Key Infrastructure (PKI).  What is Diffie–Hellman key exchange used for?  Explain.
3. Describe how Diffie-Hellman algorithm used for key exchange is vulnerable to man in middle attack? Determine the shared secret key in a Diffie-Hellman scheme with a common prime 71 and primitive root 7. Given the private keys of the communicating parties A and B are 5 and 12 respectively.
4. Describe birthday attack. And explain authentication requirements and hash functions. 
5. Draw and explain blockchain architecture in detail. 

SET-6:

1. How does Blockchain differ from relational databases?  What are the types of records that are present in the blockchain database?
2. List any two financial applications that can make use of blockchain technology.  How blockchain can be used in the supply chain management with example?
3. What are the primary benefits of immutability in blockchain.   Discuss in detail about the major elements of blockchain ecosystem.
4. Explain the concept of blocks in blockchain technology. What is the block size of a block in the Bitcoin and the Ethereum blockchain.
5. Why is consensus mechanism required in the blockchain?  Explain different types of consensus algorithms.