Anna University , Chennai

Department of B.E-Electronics and Communication Engg

Seventh Semester

EC2035 Cryptography And Network Security

Unit 1 & 2 Question Bank

(Regulation 2008)

UNIT-I

PART-A

1. What is the difference between a mono alphabetic and a poly alphabetic cipher?

2. What is an avalanche effect in DES Algorithm?

3. What are the disadvantages of double DES?

4. Give the types of attack.

5. List out the problems of one time pad?

6. Write down the purpose of the S-Boxes in DES?

7. Differentiate between block and stream ciphering.

8. What is data confidentiality?

9. What is security mechanism?

10. What is brute force attack?

11. What is steganography?

12. What is traffic padding?

13. Why triple DES? Why not double DES?

14. What are the advantages and limitations of OFB?

15. What is electronic code book mode?

16. What are the various technique used in steganography?

17. What are the differences between link and end-to-end encryption?

18. What is middle man attack and replay attack?

19. What are the types of information that can be derived from a traffic analysis attack?

20. What is cryptography and cryptanalysis?

PART B

1. Using play fair cipher algorithm encrypt the message using the key "MONARCHY" and explain the poly alphabetic key.(16)

2. Explain 1.ceaser cipher 2. Mono alphabetic cipher 3.one time pad cipher (16)

3. Explain the Key Generation, Encryption and Decryption of DES algorithm in detail. (16)

4. Explain in detail the key generation in AES algorithm and its expansion format. (16)

5. a. Explain single round DES with neat sketch.(10)

b . Explain Double &Triple DES with keys.(6)

6. Explain the block cipher modes of operation. (16)

7. Explain the OSI security model. (16)

8. a. Explain various transposition ciphers in detail. (8)

b. Explain the basic principle of rotor machine. (8)

9. Explain in detail about Feistel cipher with diagram. (16)

10. a. Explain classical encryption techniques with symmetric cipher model. (12)

b. Explain steganography in detail. (4)

UNIT-II

PART-A

1. Differentiate between symmetric key and public key cryptography.

2. What are the attacks on the RSA algorithm?

3. What is an elliptic curve and define diffusion.

4. Define Euler’s totient function (used in RSA algorithm).

5. Why do we need Diffie Hellman algorithm?

6. What is public key certificate?

7. Specify the applications of the public key cryptosystem?

8. What is a one way function?

9. Define Euler’s theorem and its application?

10. Describe in general terms an efficient procedure for picking a prime number?

11. Define Fermat Theorem?

12. What is the primitive root of a number?

13. What is a trapdoor one way function?

14. What are essential ingredients of the public key directory?

15. Differentiate public key and conventional encryption?

16. What are the principle elements of a public key cryptosystem?

17. What are roles of public and private key?

18. What requirements must a public key cryptosystem to fulfill to a secured algorithm?

19. List four general characteristics of scheme for the distribution of the public key.

20. Write about Chinese Remainder Theorem.

21.what is key distribution?

PART-B

1. Explain briefly about Fermats and Eulers theorems. (16)

2. a. With the step involved explain Diffie Hellman key exchange algorithm in detail. (8)

b. Users A and B use the Diffie Hellman key exchange technique with a common prime q=71 and primitive root α=7.If A has private key XA=5 what is A public key YA? (8)

3. a. Explain briefly about RSA and discuss its merit. (8)

b. Perform using encryption and decryption using RSA algorithm for p=3,q=11,e=7 and for message M=5.(8)

4. State and explain the principles of public key cryptography. (16)

5. Explain the key management of public key encryption in detail. (16)

6. Explain ECC - Diffie Hellman key Exchange with both keys in detail with an example. (16)

7. Write about elliptic curve architecture in detail and how they are useful for cryptography. (16)

8. a. Write about key distribution in detail. (10)

b. Explain the purpose of CRT. (6)

9. Explain the different methods used in random number generation. (16)

10. What are the requirements and applications of public key? Compare conventional with public key encryption. (16)

Attachment :

EC2035 CNS QB - Unit 1 2.pdf (Size: 201.62 KB / Downloads: 1,688)