Total No. of Questions 18] [Total No. of Pages 02
M.Sc. DEGREE EXAMINATION, MAY 2018
Second Year
COMPUTER SCIENCE
Cryptography and Network Security
Time 3 Hours Maximum Marks :70
SECTION A
Answer any three of the following questions. x 15 45)
Q1) Discuss about different Classical Encryption Techniques.
Q2) Explain about Chinese Remainder theorem and Euler's theorem with
example.
Q3) Describe Encryption and decryption functions of Triple DES. Compare its
strength with DES.
Q4) Differentiate between hashing and encryption. What are the practical
applications of hashing? Compare MD5 and SHA1 hashing algorithms.
Q5) With a neat sketch explain the IPSec scenario and IPSec Services.
SECTION B
Answer any five of the following questions. x 4 20)
Q6) What are the two approaches to attacking a cipher? What is the difference
between a block cipher and a stream cipher?
Q7) Write differences between substitution techniques and transposition techniques.
Q8) How are keys generated in Cast-128 algorithm?
Q9) Explain RSA Algorithm with example.
Q10) What are the similarities and differences between MIME and PGP?
Q11) State and explain Fermat's.
Q12) What is digital signature? Explain its use with the help of example.
Q13) What is a firewall? What is the need for firewalls?
SECTION C
Answer all questions. x 1
Q14)Define public key.
Q15) Define steganography.
Q16) What is AES?
Q17) Define Diffi Hellman key exchange.
Q18) What is Kerberos?