It1352- Cryptography And Network Security

IT1352- Cryptography and Network Security(2007)

PART-A 2*10=20 1.What is cryptography? 2.Give any four names of substitution techniques 3.What are the services defined by x.800? 4.What is the purpose of Diffie-Hellman algorithm? 5.Define man in the middle attack 6.List design objectives for HMAC 7.What is MAC? 8.What are the requirements for digital signature? 9.Give the Kerberos simple dialogue 10.What is firewall? PART-B 5*16=80 11 a(i) Briefly explain about OSI security architecture (8 ) (ii) Explain briefly about data encryption standard (8 ) (OR) b(i) Explain briefly about block cipher principles and modes of operation (12) (ii) Explain about traffic confidentiality (4) 12 a(i) Explain briefly about Diffie-Hellman key exchange (16) (OR) b(i) Explain briefly about public key cryptography (8 ) (ii) What is the use of RSA algorithm? (8 ) 13 a(i) Expalin briefly about MD5 message digest algorithm (12) (ii) What is the use of authentication protocols? (4) (OR) b(i) Explain briefly about RIPEMD (16) 14 a(i) Explain about Kerberos (16) (OR) b(i) Explain briefly about web security (16)

15 a(i) Discuss the design principles of firewall (8 ) (ii) What is meant by password management? (8 ) (OR) b(i) What is meant by virus and explain briefly about threats? (16)