# CSVTU QUESTION PAPER

## B. E. VII Sem, ET & T, APR-MAY 2009

## CRYPTOGRAPHY & SECURE COMMUNICATION

**Note :** Attempt any two parts from (b) ,(c) & (d) of each questions.

**Q.1** **(a)** What is a discrete algorithm? 2

**(b)** State the difference between Fermat’s Little Theorem & Euler’s theorem along with applications. 7

**(c)** Which one is the best method of key management? Draw its schematic model with suitable example. 7

**(d)** How RSA Cryptography works? Explain all about RSA algorithm with separate algorithms of its ingredients. 7

**Q.2** **(a)** Using Euclid’s Algorithm determine the greatest common divisor of (64,24) 2

**(b)** Explain Secrecy & Authentication .How they are achieved in public key cryptosystem? 7

**(c)** Why the hash functions are used in cryptography & secure communication. Write the methods of checking integrity. 7

**(d)** Write the Brute force attack algorithm. Briefly explain about the operation of Brute force attack. 7

**Q.3** **(a)** Define the term MD.List out the versions of MD. 2

**(b)** What are the digital signature standards? Name it & explain in brief. 7

**(c)** Explain the exchange of session keys between client & server using Kerberos. 7

**(d)** Write the MD-5 message digest algorithm & also give reason for its working. 7

**Q.**4 (a) Whether IP security & web security are same? Give reason to support your answer. 2

**(b)** How the threats are affecting to web security & traffic security? 7

**(c)** Draw the IP security architecture with its advantages & disadvantages. 7

**(d)** Explain SSL architecture & define its protocol which is supporting to it. 7

**Q.**5 (a) List out the advantage & disadvantages of Steganography. 2

**(b)** What is a spread spectrum steganography?Write its significance. 7

**(c)** Give the difference between Cryptography & Stegaogaphy (At least five). 7

**(d)** What are the aspects of deterministic & in deterministic model of information theory in case of steganography? 7

CSVTU Exam Paper Cryptography & Secure Communication Apr- May 2009