Cryptography & Network Security Unit 2 – Mathematical Foundations, AES and Public Key Cryptography: important questions for AKTU
Unit 2 (Mathematical Foundations, AES and Public Key Cryptography) questions that AKTU repeats most often. This unit carries about 32 marks per paper. Start with the repeated questions, then the most asked topics.
Most repeated Unit 2 questions
- State and prove Fermat’s theorem. Use Fermat theorem to find a number ‘a’ between0 and 72 with a≡9794 mod 73. (10 marks, 2024, Fermat Theorem) – also asked in 2023
- State Chinese remainder theorem (CRT). Solve the following congruent equations by CRT: (i) X=2 mod 3; (ii) X=3 mod 5. (10 marks, 2024, Chinese Remainder Theorem) – also asked in 2018
- What do you understand by Chinese Remainder Theorem? Solve the following congruent equations by Chinese remainder theorem: (i) X ≡ 2 mod 3; (ii) X ≡ 3 mod 5; (iii) X ≡ 2 mod 7. (10 marks, 2023, Chinese Remainder Theorem) – also asked in 2021
Most important Unit 2 topic
- Extended Euclidean Algorithm (Unit 2: Mathematical Foundations, AES and Public Key Cryptography) – asked 9 times in 2018, 2020, 2021, 2022, 2023, 2024, 2025, 2026
Most asked Unit 2 topics
- Extended Euclidean Algorithm – asked 9 times
- Chinese Remainder Theorem – asked 8 times
- Advanced Encryption Standard (AES) – asked 7 times
More Unit 2 previous year questions
- State Chinese remainder theorem. (2 marks, 2026, Chinese Remainder Theorem)
- State Fermat’s Little Theorem. (2 marks, 2026, Fermat Theorem)
- Calculate Φ(35). (2 marks, 2026, Euler Theorem)
- Write algorithm for primality test. How it works. (7 marks, 2026, Primality Testing)
- Explain modular arithmetic and Extended Euclidean Algorithm with example. (7 marks, 2026, Extended Euclidean Algorithm)
Unit 2 syllabus topics
- Groups
- Fields
- Finite Fields GF(p)
- Modular Arithmetic
- Prime and Relatively Prime Numbers
- Extended Euclidean Algorithm
- Advanced Encryption Standard (AES)
- Fermat Theorem
- Euler Theorem
- Primality Testing
- Chinese Remainder Theorem
- Discrete Logarithmic Problem