CB3491 Cryptography and Cyber Security Previous Year Question Papers - Anna University

UNIT I: Introduction and Number Theory

Part A (2 Marks)

• Define Cryptography and Cryptanalysis.
• What is the difference between a Monoalphabetic and Polyalphabetic cipher?.
• Define Steganography and its common techniques.
• Explain the "Avalanche Effect" in encryption.

Part B (13/16 Marks)

• OSI Security Architecture: Detailed explanation of the model with a neat diagram.
• Classical Encryption Techniques: Thorough discussion of substitution and transposition techniques with examples.
• Model for Network Security: Components and working mechanism.
• Foundations of Modern Cryptography: Perfect security and information theory.

UNIT II: Symmetric Ciphers

Part A (2 Marks)

• State the disadvantages of Double DES.
• What are the four different stages of the AES encryption process?.
• Explain the role of S-boxes in the DES algorithm.
• Briefly describe the working principle of the RC4 stream cipher.

Part B (13/16 Marks)

• Data Encryption Standard (DES): Detailed architecture, encryption process, and evaluation of its strength.
• Advanced Encryption Standard (AES): Systematic structure, round functions, and comparison with DES.
• Block Cipher Modes of Operation: Explanation of ECB, CBC, CFB, OFB, and Counter modes.
• Mathematical Foundations: Groups, rings, and finite fields in symmetric key cryptography.

UNIT III: Asymmetric Cryptography

Part A (2 Marks)

• State Euler's Totient function and its significance.
• What is the Discrete Logarithm Problem?.
• Define Public-Key Certificate and its requirements.

Part B (13/16 Marks)

• RSA Algorithm: Key generation, encryption/decryption steps, and possible security threats.
• Diffie-Hellman Key Exchange: Working mechanism, an illustrative example, and vulnerability to Man-in-the-Middle attacks.
• Chinese Remainder Theorem (CRT): Statement, proof, and its application in cryptographic computations.
• Elliptic Curve Cryptography (ECC): Arithmetic operations, Diffie-Hellman using ECC, and its advantages over RSA.

UNIT IV: Message Authentication and Integrity

Part A (2 Marks)

• Distinguish between a Hash function and a Message Authentication Code (MAC).
• What are the requirements for a digital signature?.
• Briefly explain the role of X.509 certificates in security.

Part B (13/16 Marks)

• Hash Functions: Detailed study of SHA and the structure of HMAC.
• Digital Signatures: Principles, requirements, and standard algorithms.
• Authentication Protocols: Architecture and certification mechanisms in Kerberos.

UNIT V: Cyber Security and Social Engineering

Part A (2 Marks)

• What is SQL Injection and its potential consequences?.
• Define "Phishing" and its impact on cyber security.
• What is the difference between active and passive security threats?.

Part B (13/16 Marks)

• Classification of Cyber Crimes: Comprehensive overview and real-world examples.
• Network Security: In-depth look at Cloud, Web, and Wireless security protocols.
• Tools and Methods: Common techniques used in cyber crimes and their countermeasures.

Most Repeated / High-Weight Questions

DES and AES encryption algorithms, RSA key generation and encryption, Diffie-Hellman key exchange, hash functions and digital signatures, block cipher modes of operation, cyber attack classification and countermeasures.