BSc CSIT (TU) Science Cryptography (BSc CSIT, CSC316) Question Paper 2077
This is the official BSc CSIT (TU) (Science stream) Cryptography (BSc CSIT, CSC316) question paper for 2077, as set in the regular annual examination. It carries 60 full marks and a time allowance of 180 minutes, across 12 questions. On Kekkei you can attempt this Cryptography (BSc CSIT, CSC316) past paper online with a timer, get instant AI feedback and step-by-step solutions, and track the topics where you lose marks — completely free. Whether you are revising for your BSc CSIT (TU) Cryptography (BSc CSIT, CSC316) exam or solving previous years' question papers, this 2077 paper is a great way to practise under real exam conditions.
Section A: Long Answer Questions
Attempt any TWO questions.
Explain the structure of the Advanced Encryption Standard (AES) algorithm. Describe the four transformations: SubBytes, ShiftRows, MixColumns and AddRoundKey with examples.
Explain the Diffie-Hellman key exchange algorithm with an example. Show how an eavesdropper can perform a man-in-the-middle attack on this protocol.
What are cryptographic hash functions? Explain the SHA-1 algorithm and describe how a 160-bit message digest is generated.
Section B: Short Answer Questions
Attempt any EIGHT questions.
Explain the ElGamal cryptographic system for encryption and decryption.
Differentiate between block ciphers and stream ciphers. Explain the different modes of operation of block ciphers.
What is a Message Authentication Code (MAC)? Explain how HMAC works.
Explain key management and key distribution in symmetric cryptography.
State and explain Fermat's little theorem and Euler's theorem with examples.
Is a man-in-the-middle attack possible in the Diffie-Hellman algorithm? Justify your answer.
Explain the families of SHA-2 and their differences from SHA-1.
What is Public Key Infrastructure (PKI)? Explain the role of a Certificate Authority and digital certificates.
Explain the basic logic of malicious code: viruses, worms and trojan horses.