Kannur University 2007 M.C.A Computer Aplications ,uary C 4.4 CRYPTOGRAPHY AND NETWORK SECURITY - Question Paper

Fourth Semester M.C.A Degree Examination,January 2007
MCAC 4.4 CRYPTOGRAPHY AND NETWORK SECURITY
Time:3 Hours Max.Marks :80

Instructions: 1)Answer any 5 ques.
2)All ques. carry equal marks (16x5=80)


1.Define gcd of 2 integers a and b.Show that if c=gcd(a,b) then c can be expressed as in the form c=ax+by where x and y are integers.Find the multiplicative inverse of 286 modulo 1575 if exists.

2.Breifly discuss Ceaser Cipher ,monoalphabetic and Play Fair ciphers?

3.What is DES? Comment on security of DES.Give various versions of DES.

4.Briefly discuss the concept of key -management in cryptography.

5.Briefly discuss the message authentication codes?

6.Explain secure hash algorithm.

7.What are the requirements of digital signature?Draw a block diagram of digital signature scheme using RSA approach and discuss.

8.Explain intrusion detection techniques.

Earning:   Approval pending.