Cryptography & Network Security Unit 2 – Mathematical Foundations, AES and Public Key Cryptography: AKTU previous year questions
12 AKTU questions from Unit 2 (Mathematical Foundations, AES and Public Key Cryptography) asked in 2025–2026, tagged by marks, year and topic. In short: about 32 marks of every paper come from this unit; the most asked topic is Extended Euclidean Algorithm (9 times); 3 questions came back in a later year. The latest ones are listed below; on the page you can filter them by 2-mark or long questions, topic and repeats.
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)
- State and prove Euler’s theorem. (7 marks, 2026, Euler Theorem)
- Describe the AES encryption and decryption process. (7 marks, 2026, Advanced Encryption Standard (AES))
- Explain the structure single round of AES. (7 marks, 2026, Advanced Encryption Standard (AES))
- Explain RSA algorithm along with its security considerations. (7 marks, 2026, RSA Algorithm)
- Determine GCD of (1970, 1066) using Euclid’s algorithm. (2 marks, 2025, Extended Euclidean Algorithm)
- Compute Φ(55). (2 marks, 2025, Euler Theorem)
- Explain the Advanced Encryption Standard (AES) algorithm, providing a clear diagram that illustrates its architecture. (10 marks, 2025, Advanced Encryption Standard (AES))
Most asked Unit 2 topics
- Extended Euclidean Algorithm – asked 9 times
- Chinese Remainder Theorem – asked 8 times
- Advanced Encryption Standard (AES) – asked 7 times
Unit 2 question pattern
- 2-mark questions: 5 asked in 2025–2026
- 7-mark questions: 6 asked in 2025–2026
- 10-mark questions: 1 asked in 2025–2026
- About 32 marks from Unit 2 in every paper
- 3 questions were asked again in a later year
Unit 2 questions year by year
- 2026: 9 Unit 2 questions asked (48 marks across that year's papers)
- 2025: 3 Unit 2 questions asked (14 marks across that year's papers)