Cryptography Model Question Paper Mca 5th Sem 5l5a6z

ST. ALOYSIUS INSTITUTE OF MANAGEMENT AND INFORMATION TECHNOLOGY[AIMIT] ST ALOYSIUS COLLEGE(AUTONOMOUS) V SEM M.C.A EXAMINATION DEC 2012 SUB CODE : P605.5 PAPER : CRYPTOGRAPHY AND NETWORK SECURITY TIME 3HRS MAX MARKS :100 Note Answer any FIVE questions. Each question carries 20 marks.

1 A Define security “services”, “attacks”, and “mechanism”, also 10M give classification of security services and attacks and describe them briefly B With a neat diagram explain symmetric cipher model

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2 A Explain playfair cipher. Discuss its encryption ,decryption 10M using the following data Plain Text: A lifetime of training for just ten seconds. KEY : Gates B Explain single columnar and double columnar transposition ciphers 10M Discuss single columnar encryption and decryption using the following data Plain text: Treat your like your toothbrush. Don't let anybody else use it, and get a new one every six months. Key : Computer

3 A With a neat diagram discuss encryption using DES algorithm B State and prove Fermats theorem

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4 A With a neat diagram explain encryption and authentication using public key cryptography

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B Explain the RSA algorithm and discuss the timing attacks on RSA

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algorithm. Let p=7 , q=11, e=17 , M=8 perform encryption and decryption using the RSA algorithm 5 A Explain Miller-Rabin algorithm of testing of primality .

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Using the algorithm check whether 29 is prime or not

B Describe Diffie – Hellman Key Exchange. Let s A and B use the Diffie-Hellman key exchange technique a common prime q=71 and a primitive root α =7 i) if A has private key XA =5 , what is A’s public key YA?

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ii) if B has private key XB =12 , what is B’s public key YB? iii) What is shared secret key? 6 A B 7 A B

With a neat diagram explain blowfish algorithm Write a note on IP Security Architecture

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Discuss the different methods of distribution of public keys.

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Briefly Discuss Electronic Mail Security.

8 A Explain following with examples Virus, worms, Trojan horse

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B What is a firewall? And With a neat diagram explain the main 10M types of firewall?

Model question paper 2:

ST. ALOYSIUS INSTITUTE OF MANAGEMENT AND INFORMATION TECHNOLOGY[AIMIT] ST ALOYSIUS COLLEGE(AUTONOMOUS) V SEM M.C.A EXAMINATION DEC 2012 SUB CODE : P605.5 PAPER : CRYPTOGRAPHY AND NETWORK SECURITY TIME 3HRS MAX MARKS :100 Note Answer any FIVE questions. Each question carries 20 marks. 1 A What are the essential ingredients of a symmetric cipher? 10M

Explain with a neat diagram B Briefly explain the following 10M i)cryptography ii)plain text and cipher text iii)cryptology iv)cryptanalysis v)Decryption 2 B Briefly explain the hill cipher and discuss the encryption and 10M decryption of the plain text “COE” using the key “ANOTHERBZ” C Discuss encryption, decryption and cryptanalysis of the 10M following substitution ciphers 1.Caesar cipher 2.Monoalphabetic cipher 3 A With a neat diagram explain different Block Cipher modes of Operation B With a neat diagram explain simplified DES in detail

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4 A What are the difference between conventional and public key encryption B What are the requirements of public key cryptography

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C Explain the RSA algorithm and discuss the attacks on RSA algorithm.

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Let p=11, q=13, e=11, M=8 perform encryption and decryption using the RSA algorithm

5 A State and prove Eulers theorem B Explain digital signature algorithm?

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6 A With a neat diagram explain the following cipher models i) Electronic code book mode ii) Output mode iii) Cipher feed back mode iv) Counter mode Write a note on B

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7 A B

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i) stegnography ii) X.509 Authentication Service. Discuss the different methods of distribution of public keys.. What is a firewall? And With a neat diagram explain the main types of firewall?

8 A Explain briefly about the trusted systems B Explain the different types of management best practices?

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