M.Sc. (Semester IV) (CBCS) Examination Nov/Dec-2018
Computer Science
NETWORK SECURITY
Time: 2½ Hours Max. Marks: 70
Instructions: Q.1 and Q.2 is compulsory.
Attempt any three questions from Q. 3 to 7.
Figures to the right indicate full marks.
Q.1 Choose the correct alternatives: 10
Which of the following attack is not a threat to the integrity of data?
Masquerade Modification
Repudiation Snooping
Which RFC document includes a definition of security service?
RFC 2828 RFC 2401
RFC 3310 RFC 6600
Which of the following is a component of cryptography?
Ciphertext Ciphers
Key All of these
In public-key cryptography, key is used for encryption
Public Private
Both a and b Shared
There are encryption round in IDEA.
16 5
10 8
In asymmetric-key cryptography, how many keys are required for each
communicating party?
2 3
4 1
Which of the following services is not provided by digital signatures
directly?
Message authenticity Message Confidentiality
Message Integrity Nonrepudiation
Who issues PGP certificates?
ITU-T IEEE
IETF The users themselves
In which protocol is the payment gateway used?
SET PGP
TLS SSL
10) firewall is mostly used in small businesses.
Packet filtering Circuit-level gateway
Application level gateway None of these
Page 2 of 2
SLR-VG-227
State true or false: 04
The loss of integrity is the unauthorized modification of information.
Enveloped data is not the function of S/MIME.
SHA-1 length is 150 bit.
SET stands for Secure Electronic Transactions.
Q.2 Write short note. 08
Password protection approaches
Cryptanalysis
Answer the following: 06
How is the S-box constructed?
What does meant by a trusted system?
Q.3 Answer the following: 14
Explain various network security services.
Briefly explain the model for network security.
Q.4 Answer the following: 14
Explain DES with its structure. Also explain its function.
Explain the sub-key generation in the IDEA algorithm.
Q.5 Answer the following: 14
How does the PGP use the concept of trust and legitimacy?
Explain the S/MIME protocol.
Q.6 Answer the following: 14
What do you mean by the term intruder? Explain intrusion techniques in brief.
Explain any two approaches for intrusion detection.
Q.7 Answer the following: 14
What is key management? Also explain the function of key management.
Discuss the direct and arbitrated approaches for digital signature.