Birla Institute of Technology (BIT Mesra) 2007 MS Software Engineering Network Security - Question Paper

Birla Institute of Technology and Science, Pilani
Distance Learning Programmes Division
MS Software Engineering in Collaboration with Wipro Technologies
Second Semester 2006 – 2007
Mid-semester exam
Regular
Course No. : SEWP ZG513
Course Name : Network Security
Nature of examination : Closed Book Bangalore
Weightage : 40 %
Duration : two Hours No of pages : 1
Date : March 18, 2007 (AN) No. of questions : 8


Note : Attempt all ques.. begin every ans from a fresh page.

1 ) Differentiate ranging from
a) Confusion and Diffusion.
b) Passive and Active Attacks. -5-

2) With neat diagrams discuss Encryption & Decryption in the Cipher Block Chaining
mode. -5-

For the provided Ciphertext and the Key, obtain the Plaintext, if double transition of columns was employed by the sender.

Ciphertext : E S A Y T P G R Y A H P C R O I S Y
Key : two four one five three six for both rounds -5-

For the provided Ciphertext and the Key, obtain the Plaintext, if Playfair Cipher was employed by the sender.

Ciphertext : R Z Y W U D C M A T I C A G C R C T G P S L
Key : WIPROWASE -5-

5) discuss the single round of DES Algorithm with a neat schematic diagram. -5-


6) With suitable diagrams, show how Public Key Encryption can be used in Confidentiality ,Authentication and both. -5-


7) In a Public Key system using RSA ,you intercept the cipher text
C=10 sent to a user whose public key is e=5, n=35. What is plain text M. -5-


8) elaborate the 3 main actions of a Packet Filter. -5-


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Earning:   Approval pending.