Information security — Summer 2025

What are the key principles of security?

Differentiate between cryptography and steganography.

What is cryptanalysis? Explain 5 techniques of how attackers can launch attacks. 0

What would be the transformation of a message ‘Happy Birthday to you’ using Rail 0 Fence technique level =3?

What is the idea behind meet-in-the-middle attack?

Explain the steps in the various rounds of DES.

Explain the steps in the various rounds of AES.

What is an Initialization Vector(IV)? What is its significance?

Generate a Cipher text for plain text ‘ACT’ with key ‘GYBNQKURP’ using hill cipher.

Explain RSA algorithm and also compute public key and private key of RSA with p- 53, q=59 and e = 3.

Differentiate between diffusion and confusion with example

Generate a Cipher text for plain text ‘MISSION’ with key ‘IMPOSSIBLE’ using playfair cipher.

Explain the Deffie Hellman key exchange algorithm in detail. In a Diffie Hellman Key Exchange, Alice and Bob have chosen prime value 11 and 7. If Alice’s secret key is 3 and Bob’s secret key is 6, what is the secret key they exchanged?

Differentiate between Session key and Master key.

Why is SHA more secure than MD5?

Discuss X.509 Certificates.

What are the common causes for revoking a digital certificate?

What is the difference between MAC and message digest?

Discuss Secure Hash Algorithm (SHA)

Explain the following properties of hash function (i) One way property (ii) Weak collision resistance

Name the four key steps in the creation of a digital certificate.

Discuss the working of KERBEROS authentication protocol.

What are the three aspects of a 3-factor authentication?

What is KDC? With the help of diagram explain how KDC do key distribution.

Discuss Digital signature algorithm.