CRYPTOGRAPHY & NETWORK SECURITY QUESTION PAPER
CRYPTOGRAPHY & NETWORK SECURITY UTU QUESTION PAPER
Roll No.
Time: 3 Hours
Even Semester Examination, 2021-22
Course Name: B.TECH
Branch: CSE/IT
Semester: VIII
Subject: Cryptography and Network Security
Note: Attempt all questions: All Questions carry equal marks
Max Marks: 100
Number of Printed pages: 2
Q1. Attempt any four parts of the following (5 x 4 = 20)
(a) What are Confusion and Diffusion properties of Modern Ciphers?
(b) Why is asymmetric cryptography bad for huge data? Specify the reason?
(c) Differentiate between tunnel mode and transport mode of IPSec.
(d) Explain about Host-Based Intrusion Detection Systems.
(e) State and Describe Fermat's theorem.
Q2. Attempt any four parts of the following (5 x 4 = 20)
(a) Discuss any four Substitution Technique and list their merits and demerits.
(b) What do you mean by one way property in hash function?
(c) What is addition, multiplicative and additive inverses modulo 8?
(d) How is GCD calculated with Euclid's algorithm? Calculate the GCD of (270,192). (e) Explain the Key Expansion process in AES.
Q3. Attempt any two parts of the following (10 x 2 = 20)
(a) How does PGP provide confidentiality and authentication service for e-mail and file storage applications? Draw the block diagram and explain its components.
(b) How does screened host architecture for firewalls differ from screened subnet firewall architecture? Which offers more security for information assets on trusted network? Explain with diagram?
(c) What are the objectives of SET? What do you understand by a dual signature that is used in SET?
Q4. Attempt any two parts of the following: (10 x 2 = 20)
(a) What are the types of attacks addressed by message authentication? What are two levels of functionality that comprise a message authentication or digital signature mechanism?
(b) Explain concept of public and private key in respect of RSA Algorithms. Sohan and Mohan agreed to use RSA algorithm for the secret communication. Sohan securely choose two primes, p=5 and q=11 and a secret key d=7. Find the corresponding public key. Mohan uses this public key and sends a cipher text 18 to Sohan. Find the plain text.
(c) Explain OSI Security architecture model with diagram.
Q5. Attempt any two parts of the following: (10 x 2 = 20)
(a) What protocols comprise SSL? What is the difference between an SSL connection and an SSL session?
(b) Explain the process of deriving eighty 64-bitwords from 1024 bits for processing of a single blocks and also discuss single round function in SHA-512 algorithm. Show the values of W16, W17, W18 and W19.
(c) Define Kerberos with its Requirements. In the content of Kerberos, what is realm? Assume the client A wants to communicate server S using Kerberos procedure. How can it be achieved? Write the authentication dialogue?
0 Comments