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07TE762

USN

R. V. COLLEGE OF ENGINEERINGAutonomous Institution under VTU

VII Semester B. E. Examinations Dec-10/Jan-11Telecommunication Engineering

CRYPTOGRAPHY AND NETWORK SECURITY (ELECTIVE)

Time: 03 Hours Maximum Marks: 100

Instructions to candidates:Answer FIVE full questions selecting atleast TWO questions from PART-A andTWO questions from PART-B.

PART- A

1 a With a neat diagram, briefly describe the general model of networksecurity. Define a model for network Access security for unwanted

access such as hackers and software threats. 08b

c

What are the two types of security attacks? Explain with two examplesfor each.Give a comparison between unconditionally secure andcomputationally secure encryption scheme.

08

04

2 a Show the difference between monoalphabetic and polyalphabeticciphers. Explain their advantages and weaknesses against cryptanalysis. 06

b With a neat diagram explain the single round of DES encryption. 08c Using simpler-DES generate two 8-Bit sub-keys from a 10-Bit key.

P8 Table

6 3 7 4 8 5 10 9

key input1010001010(10 Bits)Generate 2 sub keys K1 and K2. ( 8Bits) 06

3 a Define the message authentication (MAC)and Hash Functions (H) andshow how the confidentially and Authentication are achieved usingHash Coding. 08

b Derive message Authentication Code based on DES. 04c Give the Authentication Dialogue for Kerberos-ver-4.Explain the

difference between version-4 and 5. 08

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4 a Describe the five services provided by PGP (Pretty Good privacy). 08b With a diagram explain the Format for X-509 certificate. 06c Briefly explain various MIME transfer Encodings. 06

PART- B

5 a Explain the transport and Tunnel mode for IP security providing

Secured Communication. 08b What is security Association? Give the Basic Combinations of SA. 08c Mention important features of Oakley key algorithm. 04

6 a Explain the operation of SSL Record protocol. 08b Define the principal categories of SET (Secure Electric Transactions)

participants. 06c Mention parameters used to define session states and connection

states in SSL specifications. 06

7 a Give an architecture for the distributed intrusion detection system andexplain. 08

bc

Explain the password management in UNIX.Explain Honeypot intrusion Detection Technology.

0606

8 a Give the taximony of Malicious programs and explain. 06b With diagrams illustrate common types of firewalls. 06c Write short notes on any two of the following:

a. Radix 64-conversion.b. Virus life cyclec. Boston Hostd.

Worm propagatione. Application level gateway. 08