Andhra University 2005-2nd Year B.Tech Information Technology Forth Semester - CRYPTOGRAPHY AND NETWORK SECURITY - Question Paper

MODEL PAPER

B. Tech (IT) Degree exam

Forth Year - 2nd Semester

CRYPTOGRAPHY AND NETWORK SECURITY

Time: three hrs
Max Marks: 70

First ques. is Compulsory

ans any 4 from the remaining ques.

All ques. carry equal marks

ans all parts of any ques. at 1 place

1. a) What is Non-repudiation?
b) What is denial service attack?
c) Distinguish ranging from stream and block ciphers
d) obtain the value of 89 mod 17
e) What is electronic money?
f) What is a digital envelope?
g) What is session key?

2. a) define the Diffie - Hellman key exchange algorithm and discuss it with an example.
b) Alice and Bob want to establish a secret key using the Diffie - Hellman key exchange protocol using n = 11, g = 5, x = two and y = 3. obtain the values A and B and the secret key.

3. define the data encryption algorithm.

4. a) elaborate the key requirements of message digests?
b) define the secure hash algorithm.

5. a) define the steps in the creation of a digital certificate.
b) explain XML security concepts.

6. a)Describe the time stamping protocol. What is its significance?
b) define pretty good privacy.

7. a) What is password based encryption? elaborate the issues associated with it?
b) define the KERBEROS protocol.

8. a) elaborate the characteristics of a good firewall implementation?
b) What is a VPN? discuss briefly about the VPN architecture.

Earning:   Approval pending.