B.Sc. (Computer Science) Sem 5 Information and Network Security Nov 2024 Question Paper - Mumbai University | munotes

Questions asked in this paper

• N.B. (1) All questions are compulsory. (2) Figures to the right indicate marks. (3) Illustrations, in-depth answers and diagrams will be appreciated. (4) Mixing of sub-questions is not allowed.

SECTION I - Q.1 (Attempt ANY FOUR from the following) 20 Marks

1. (a) Differentiate between substitution technique and transposition technique in encryption.
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2. (b) Briefly define categories of security mechanism.
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3. (c) State and explain steps involved in RSA Algorithm.
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4. (d) Using a simple columnar transposition cipher, encrypt the given plaintext message. Plaintext: NETWORKSECURITY, Key: LEMON
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5. (e) What are the components of simple symmetric cipher model? Explain with suitable diagram.
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6. (f) Describe the Feistel Structure of encryption & decryption.
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SECTION II - Q.2 (Attempt ANY FOUR from the following) 20 Marks

1. (a) Define message authentication. What are the requirements of message authentication?
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2. (b) Describe X.509 certificate format with suitable diagram.
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3. (c) What is the purpose of the Secure Hash Algorithm (SHA) in cryptographic applications? Explain how variants of SHA differ from one another?
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4. (d) Explain the two approaches of Digital Signature.
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5. (e) Write a note on Kerberos.
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6. (f) Alice and Bob want to securely communicate using the Diffie-Hellman Key Exchange method. Given the following parameters: Prime number p = 5, Generator g = 3, Alice's private key = 3, Bob's private key = 2. Calculate Alice's public key, Bob's public key. And also compute the shared secret key using the public keys.
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SECTION III - Q.3 (Attempt ANY FOUR from the following) 20 Marks

1. (a) How does Pretty Good Privacy (PGP) encryption work?
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2. (b) Describe Secure Electronic Transaction (SET).
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3. (c) Write a short note on Secure/Multipurpose Internet Mail Extensions (S/MIME).
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4. (d) Explain IP security architecture.
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5. (e) Define virus. State and explain any four types of viruses.
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6. (f) What is Intrusion Detection System (IDS)? State and explain different types of IDS.
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SECTION IV - Q.4 (Attempt ANY FIVE from the following) 15 Marks

1. (a) Explain any two active attacks with suitable illustration.
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2. (b) State design objectives of HMAC.
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3. (c) What is packet filtering firewall?
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4. (d) How does Electronic Code Book (ECB) encryption mode operate?
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5. (e) Explain three characteristics of hash function.
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6. (f) Define the role of honeypots.
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