Hemchandracharya North Gujarat University 2004 M.Sc Computer Science Computer Security - Question Paper

DF-1706 Seat No.__________
FOURTH YEAR (CA & IT) exam
August – 2004
(406) EL – 02 : Computer Security


Time : three Hours] [Total Marks : 35


1. (a) Write any 2 :

( one ) What is computer security ? Briefly discuss personal security policy.
( two ) explain about security attacks described by X.800.
( three ) Rule based intrusion detection.

(b) Write short notes on the subsequent :

( one ) Honeyports
( two ) Circuit level gateway.

2. (a) Write any 2 :

( one ) What is salt in the situation of UNIX password management?
( two ) What is digital immune system ?
( three ) elaborate the typical phases of operation of virus or warm ?

(b) Write short notes on the subsequent :

( one ) Play fair cipher
( two ) Primitive operations used in RC5.

3. (a) Attempt any 2 :

( one ) List ways in which secret key can be distributed to 2 communicating parties. Also discuss automatic key distribution for connection oriented protocol.
( two ) Explain RSA algorithm with example.
( three ) Briefly discuss Diffie-Hellman key exchange.

(b) Attempt the subsequent :

( one ) Briefly define substitute byte and Add round key of AES.
( two ) Pictorially represent single round of DES algorithm.


4. (a) Attempt any 2 :

( one ) What is the difference ranging from diffusion and confusion ? What is purpose of S-Boxes in DES ?
( two ) What is the difference ranging from Link and End To End encryption ?
( three ) Briefly define DSA.

(b) Attempt the subsequent :

( one ) How does PGP use the concept of trust ?
( two ) Briefly define ISAKMP header format.

5. (a) Attempt any 2 :

( one ) List ans Briefly describe the principle categories of SET participants.
( two ) What are the security problems with an intranet and extranet ?
( three ) What are the 4 levels of voice privacy in wireless systems ?

(b) Attempt the subsequent :

( one ) Discuss the problems of WAN security.
( two ) What is S/MIME ?

Earning:   Approval pending.