B.Sc. (Computer Science) Sem 5 Information and Network Security 2023-24 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) Define computer security. What are the objectives of computer security?
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2. (b) What is an active attack in security? State various types of active attacks.
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3. (c) Write a note on Steganography.
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4. (d) Encrypt the following message using Rail Fence Algorithm with key size = 4. Plaintext = they are attacking from the north.
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5. (e) Explain Electronic Code Book (ECB) mode in cryptography.
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6. (f) Differentiate substitution and transposition techniques.
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SECTION II - Q.2 (Attempt ANY FOUR from the following) 20 Marks

1. (a) Write a note on public key cryptosystem.
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2. (b) Describe X.509 certificate format.
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3. (c) Assume Alice and Bob wish to communicate secretly. Compute the shared secret key using Diffie Hellman Key Exchange. [Prime number p = 7, generator g = 3, Alice's private key = 2, Bob's private key = 4]
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4. (d) How does HMAC algorithm work?
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5. (e) Discuss the concept of a digital signature. Explain its types.
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6. (f) Explain kerberos processing in detail.
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SECTION III - Q.3 (Attempt ANY FOUR from the following) 20 Marks

1. (a) What is a firewall? State and explain various types of firewall.
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2. (b) Explain the importance of web security.
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3. (c) What is S/MIME (Secure/Multipurpose Internet Mail Extensions)? Define its key features.
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4. (d) Describe IP security architecture.
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5. (e) State and explain any 5 types of virus.
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6. (f) Write a note on honeypots.
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SECTION IV - Q.4 (Attempt ANY FIVE from the following) 15 Marks

1. (a) Define terms: i. Cryptanalysis ii. Brute Force Attack
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2. (b) What is message authentication code?
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3. (c) State any two common forms of malicious code.
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4. (d) Using Caesar cipher with key size = 3, encrypt the message "hide the gold and defend east wall"
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5. (e) What are the three properties of Hash function?
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6. (f) Explain the life cycle of viruses.
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