Network Security Instructions : (1) All questions are compulsory.

(2) Assume suitable data if necessary.

1. Attempt the following (any TWO) [10]

(a) What are the Key Principles of Security (CIA)? Explain.

(b) Explain different types of Attacks.

(c) What is Shift Cipher (Caesar Cipher)? Explain with an example.

(d) Write a short note on One-Time Pad or Playfair Cipher.

2. Attempt the following (any TWO) [10]

(a) Describe the 5 steps in each round of DES.

(b) Explain the 4 steps in each round of AES.

(c) Write a short note on IDEA algorithm.

(d) Describe any 2 Modes of algorithms.

3. Attempt the following (any TWO) [10]

(a) Compare Symmetric & Asymmetric Key Cryptography.

(b) Explain any one Hashing Algorithm in detail (MD5/SHA-1).

(c) What is Key Wrapping (Digital Envelope Concept)? How is it useful?

(d) Describe RSA algorithm with an example.

4. Attempt the following (any TWO) [10]

(a) What are the 4 steps in creation of Digital Certificate.

(b) How does CA sign a Digital Certificate? How will the end user verify that

Digital Certificate?

(c) Explain concept of Chain of Certificates (CA’s Hierarchy)

(d) Write a short on PKIX Services.

5. Attempt the following (any TWO) [10]

(a) Explain the various participants in SET (Secure Electronic Transaction).

(b) List all sub-protocols of SSL and explain any one in detail.

(c) What is Packet Filter Firewall? Explain

(d) List & explain steps of PEM Email Security Protocol.

6. Attempt the following (any TWO) [10]

(a) Explain the working of Kerberos Protocol.

(b) Write a short on Authentication Based Token Method.

(c) What are the problems associated with Clear Text Passwords explain with

all steps and how to overcome.

(d) What is Random Challenge-Random Response Authentication Mechanism.