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Wednesday, 9 September 2026

Question Bank on Cryptography & Network Security

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Frequently Asked Questions (FAQ)


UNIT-1

Multiple Choice Questions:

1.  The _______________ attack is related to confidentiality.
  • Fabrication
  • Interception
  • Interruption
  • Modification
2.  If the recipient of the message has to be satisfied with the identity of the sender, the principle of ________________ comes into picture.
  • Authentication
  • Confidentiality
  • Integrity
  • Access control
3.  The ______________ attack is related to availability. 
  • Fabrication
  • Interception
  • Interruption
  • Modification

4.  If we want to ensure the principle of __________________, the content of a message must not be modified while in transit.
  • Authentication
  • Access control
  • Confidentiality
  • Integrity

5.  Interruption attacks are also called as ______________ attack. 
  • Alteration
  • Denial of Service (DoS)
  • Masquerade
  • Replay attacks


    Descriptive Questions (2 Marks):

    1. Define Cryptography.
    2. What is steganography? How is it different from cryptography?
    3. What is masquerade?  Which principle of security is breached because of that?
    4. What are replay attacks?  Give an example of a replay attack.
    5. What are the two basic functions used in encryption algorithms?
    6. Writ the differences between Symmetric and Asymmetric ciphers.
    7. What is the main difference between a stream cipher and a block cipher?
    8. Briefly define the monoalphabetic cipher.
    9. What is the difference between a monoalphabetic cipher and a polyalphabetic cipher?
    10. Differentiate between substitution and transposition techniques in classical cryptography.


    Descriptive Questions (5 Marks):

    1. Explain the importance of cryptography in the evolution of secure communication with suitable historical examples.
    2. Discuss any one of the passive attacks in detail.
    3. Discuss any two Substitution Technique and list their merits and demerits.
    4. Explain the working principle of the Caesar cipher. Encrypt the text "NETWORK" using a key value of 3.
    5. Explain the Play Fair cipher algorithm? Encrypt the message ‘MY BALLOON’ using the key ‘MONACHRY’
    6. Compare and Contrast stream ciphers and block ciphers.
    7. Explain the followings: (a) Playfair cipher. (b) Vernam cipher
    8. 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.
    9. Explain the basic principle of rotor machine.
    10. Explain the work of a Rotor Machine with a simple example. Show how a single plaintext letter is transformed through multiple rotors into ciphertext.
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    Tuesday, 8 September 2026

    Question Bank on Information Security

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    Frequently Asked Questions (FAQ)

    (Unit-1)

    Multiple Choice Questions:

    1.  Which of the following term indicates that the data is not modified by unauthorised users? 
    • Confidentiality
    • Integrity
    • Availability
    • Flexibility
    2.  Authentication is used for which of the following? 
    • Provide access rights
    • Verify identify of the user
    • Monitor systems connected to a network
    • Encrypt data at rest
    3.  Which device connects multiple networks? 
    • Hub
    • Router
    • Switch
    • Repeater

    4.  Information Security is for protecting which of the following? 
    • Hardware
    • Software
    • Data
    • Data Center

    5.  Reconnaissance means ________________. 
    • Gaining access
    • Collecting information
    • Exploiting system
    • Clearing logs

      Descriptive Questions (2 Marks):

      1. What does the CIA Triad stand for?
      2. What do you mean by "Security Attack"?
      3. Differentiate active and passive attack.
      4. Define data confidentiality.
      5. What are the ingredients of Symmetric Cipher model?
      6. List the security services available for securing a system from various attacks.
      7. What is the main purpose of a firewall?
      8. Define stream ciphers.
      9. Differentiate Symmetric and Asymmetric cryptography.
      10. List the six ingredients of public key encryption.
      11. How many modes of operations are there for implementing a Block Cipher?  What are they?
      12. Give example for mono alphabetic and poly alphabetic ciphers.

      Continue reading →
      Friday, 4 September 2026

      Project Titles for Course Project on CNS

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      Project Titles on Cryptography and Network Security

       

      S. No. 

       

      Project Title 

       

      Unit # 

       

      Key Concepts 

       

       

      1 

      Secure File Encryption System Using Classical Cryptographic Techniques 

       

       

       

      Unit I 

      Substitution techniques; Transposition techniques; Symmetric cipher model 

       

       

      2 

      Hybrid Encryption System Using Caesar, Playfair and Hill Ciphers 

       

       

      Unit I 

      Substitution techniques; Playfair cipher; Hill cipher; Classical encryption 

       

      3 

      Secure Data Hiding Using Cryptography and Steganography 

       

      Unit I 

      Steganography; Classical encryption techniques 

       

       

      4 

      Cryptanalysis and Attack Analysis of Classical Encryption Algorithms 

       

       

      Unit I 

      Classical encryption; Substitution; Transposition; Cryptanalysis and weaknesses 

       

       

      5 

      Comparative Analysis of Symmetric Encryption Algorithms 

       

       

      Unit II 

      Stream ciphers; Block ciphers; Block cipher principles; Attacks on block ciphers 

       

       

       6 

      DES-Based Secure File Encryption and Decryption System 

       

       

      Unit II

      Data Encryption Standard (DES); Block cipher principles; Encryption and decryption 

       

       7 

      Secure Communication Using RC4 Stream Cipher 

       

      Unit III 

      Stream ciphers; RC4; Symmetric encryption 

       

      8 

      AES-Based Secure Data Storage and Retrieval System 

       

       Unit III 

      Advanced Encryption Standard (AES); Block cipher 

       

      9 

      RSA-Based Secure Message Encryption and Digital Key Management 

       

      Unit III 

      Public key cryptography; RSA algorithm; Key management 

       

      10 

      Secure Key Exchange System Using Diffie–Hellman Algorithm 

       

      Unit III 

      Diffie–Hellman key exchange; Public key cryptography 

       

       

      11 

      Elliptic Curve Cryptography Based Secure Communication System 

       

       

      Unit III 

      Elliptic Curve Cryptography (ECC); Public key cryptography 

       

      12 

      Hybrid RSA–AES Encryption System for Secure File Transfer 

       

      Units II & III 

      AES; RSA; Block ciphers; Public key cryptography; Key management 

       

      13 

      Secure Password Storage Using Cryptographic Hash Functions 

       

      Unit IV 

      Cryptographic hash functions; Security requirements; Password integrity 

       

      14 

      File Integrity Verification System Using SHA-256/SHA-3 

       

      Unit IV 

      Secure Hash Algorithm (SHA); SHA-3; Data integrity 

       

       

      15 

      Secure Digital Document Authentication Using Cryptographic Hashing 

       

       

      Unit IV 

      Cryptographic hash functions; Authentication; Integrity 

       

      16 

      Comparative Security Analysis of SHA-2 and SHA-3 Hash Algorithms 

       

      Unit IV 

      SHA; SHA-3; Hash-function security requirements 

       

      17 

      Blockchain-Based Secure Academic Certificate Verification System 

       

      Unit V 

      Blockchain; Cryptographic hashing; Blockchain applications 

       

      18 

      Blockchain-Based Student Attendance Management System 

       

      Unit V 

      Blockchain; Distributed ledger; Blockchain applications 

       

       

      19 

      Blockchain-Based Secure Voting System Using Distributed Consensus 

       

       

      Unit V 

      Blockchain; Distributed consensus; Blockchain applications 

       

       

      20 

      Ethereum-Based Smart Contract for Secure Digital Transactions 

       

       

      Unit V 

      Ethereum; Smart contracts; Blockchain development platforms and APIs 

       

       

      21 

      Blockchain-Based Secure File Integrity and Data Sharing System 

       

       

      Units IV & V 

      Cryptographic hash functions; Blockchain; Data integrity; Blockchain applications 

      Continue reading →