Entity A wants to send a message "SECURITY" confidentially to the another entity B using Hill cipher. Show your calculations and the results for computing the ciphertext. Also show the calculations for the decryption of the ciphertext at receiver side to recover the original plaintext. Considered key value is given below. Note: If require use x as filler letter.
Entity A wants to send a message "SECURITY" confidentially to the another entity B using Hill cipher. Show your calculations and the results for computing the ciphertext. Also show the calculations for the decryption of the ciphertext at receiver side to recover the original plaintext. Considered key value is given below. Note: If require use x as filler letter.
Database System Concepts
7th Edition
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Chapter1: Introduction
Section: Chapter Questions
Problem 1PE
Related questions
Question
Entity A wants to send a message "SECURITY" confidentially to the another entity B using Hill cipher. Show your calculations and the results for computing the ciphertext. Also show the calculations for the decryption of the ciphertext at receiver side to recover the original plaintext. Considered key value is given below. Note: If require use x as filler letter.
Transcribed Image Text:7)
Entity A wants to send a message "SECURITY" confidentially to the another entity (10)
B using Hill cipher. Show your calculations and the results for computing the
ciphertext. Also show the calculations for the decryption of the ciphertext at
receiver side to recover the original plaintext. Considered key value is given below.
Note: If require use x as filler letter.
6 24 1
13 16 10
20 17 15
![VIT
VIT
AP
VIT AP
Introduction to Cryptography [CSE1007 - 381]
Marks: 50
Duration: 90 mins.
A
Answer all the questions.
1)
How many number of keys are required for a set of n individuals to be able to (1)
communicate with each other using secret key and public key crypto-systems.
а)
A post office sells only 3$ and 6$ stamps. Find the number of stamps a customer (1)
needs to buy to put 15$ postages on a package. Find few solutions.
c)
Jove wants to use an algebraic structure Group for his security algorithm. Suggest (1)
7*, *> will be a solution or not for Jove's security algorithm.
d)
Define the type of attack in the following case: Somehow EVE has stolen the ATM (1)
card and PIN of Alice and withdrawn money from the Alice's account.
Suggest a security mechanism/service for avoiding the attack in question part (d).
(1)
2)
Professor want to send a question paper securely to the examination coordinator. (5)
For that, professor encrypts the file using affine cipher. Anyhow student captured
the file and get to know that the file is encrypted using AFFINE Cipher and key is
(11, 4). If captured file name is "GEFD", then tell which subject paper has been
leaked.
3)
Cryptography requires sets of integers and specific operations that are defined for (5)
those sets. Two communicating parties require a cyclic Group and its generators
for their encryption/decryption algorithms. Help them to identify whether they can
use (Z18, *) if yes then find out the generators.
In cryptography often we require to compute remainders of powers of integers (5)
when divided by an integer (XY mod C). Unfortunately, XY becomes very large for
even modest sized values of Y. Joseph needs to compute 1941 modulo 21 to get
the security key for her encryption algorithm. Help out Joseph to get the required
value.
4)
В
Answer all the questions.
5)
Alice communicates some secret message to John. Attacker EVE exist in the (10)
network and capturing the communications, anyhow EVE gets to know that the
security algorithm in use is playfair cipher and key is "CRYPTOGRAPHY". If
captured ciphertext is "XFQBFQHELQBCFMDCABVFLVZBLD" then find out actual
plaintext decrypted by EVE.
6)
Commodore forwards a message "Attack tomorrow at seven am" to the captain by (10)
using most recent transposition cipher (combining two approaches) with the key [3
154 2]. Find the Ciphertext and the Decryption key, and decrypt the ciphertext to
get the plaintext back. Note: If require use x as filler letter.
Entity A wants to send a message "SECURITY" confidentially to the another entity (10)
B using Hill cipher. Show your calculations and the results for computing the
ciphertext. Also show the calculations for the decryption of the ciphertext at
receiver side to recover the original plaintext. Considered key value is given below.
Note: If require use x as filler letter.
6 24 1
13 16 10
20 17 15
-----End-----](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fe23b08fc-6609-4f83-a4d5-756c348631c1%2F669ac27d-4637-4d23-9787-48aebb487ee0%2F2u1765_processed.jpeg&w=3840&q=75)
Transcribed Image Text:VIT
VIT
AP
VIT AP
Introduction to Cryptography [CSE1007 - 381]
Marks: 50
Duration: 90 mins.
A
Answer all the questions.
1)
How many number of keys are required for a set of n individuals to be able to (1)
communicate with each other using secret key and public key crypto-systems.
а)
A post office sells only 3$ and 6$ stamps. Find the number of stamps a customer (1)
needs to buy to put 15$ postages on a package. Find few solutions.
c)
Jove wants to use an algebraic structure Group for his security algorithm. Suggest (1)
7*, *> will be a solution or not for Jove's security algorithm.
d)
Define the type of attack in the following case: Somehow EVE has stolen the ATM (1)
card and PIN of Alice and withdrawn money from the Alice's account.
Suggest a security mechanism/service for avoiding the attack in question part (d).
(1)
2)
Professor want to send a question paper securely to the examination coordinator. (5)
For that, professor encrypts the file using affine cipher. Anyhow student captured
the file and get to know that the file is encrypted using AFFINE Cipher and key is
(11, 4). If captured file name is "GEFD", then tell which subject paper has been
leaked.
3)
Cryptography requires sets of integers and specific operations that are defined for (5)
those sets. Two communicating parties require a cyclic Group and its generators
for their encryption/decryption algorithms. Help them to identify whether they can
use (Z18, *) if yes then find out the generators.
In cryptography often we require to compute remainders of powers of integers (5)
when divided by an integer (XY mod C). Unfortunately, XY becomes very large for
even modest sized values of Y. Joseph needs to compute 1941 modulo 21 to get
the security key for her encryption algorithm. Help out Joseph to get the required
value.
4)
В
Answer all the questions.
5)
Alice communicates some secret message to John. Attacker EVE exist in the (10)
network and capturing the communications, anyhow EVE gets to know that the
security algorithm in use is playfair cipher and key is "CRYPTOGRAPHY". If
captured ciphertext is "XFQBFQHELQBCFMDCABVFLVZBLD" then find out actual
plaintext decrypted by EVE.
6)
Commodore forwards a message "Attack tomorrow at seven am" to the captain by (10)
using most recent transposition cipher (combining two approaches) with the key [3
154 2]. Find the Ciphertext and the Decryption key, and decrypt the ciphertext to
get the plaintext back. Note: If require use x as filler letter.
Entity A wants to send a message "SECURITY" confidentially to the another entity (10)
B using Hill cipher. Show your calculations and the results for computing the
ciphertext. Also show the calculations for the decryption of the ciphertext at
receiver side to recover the original plaintext. Considered key value is given below.
Note: If require use x as filler letter.
6 24 1
13 16 10
20 17 15
-----End-----
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 4 steps
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.Recommended textbooks for you
Database System Concepts
Computer Science
ISBN:
9780078022159
Author:
Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:
McGraw-Hill Education
Starting Out with Python (4th Edition)
Computer Science
ISBN:
9780134444321
Author:
Tony Gaddis
Publisher:
PEARSON
Digital Fundamentals (11th Edition)
Computer Science
ISBN:
9780132737968
Author:
Thomas L. Floyd
Publisher:
PEARSON
Database System Concepts
Computer Science
ISBN:
9780078022159
Author:
Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:
McGraw-Hill Education
Starting Out with Python (4th Edition)
Computer Science
ISBN:
9780134444321
Author:
Tony Gaddis
Publisher:
PEARSON
Digital Fundamentals (11th Edition)
Computer Science
ISBN:
9780132737968
Author:
Thomas L. Floyd
Publisher:
PEARSON
C How to Program (8th Edition)
Computer Science
ISBN:
9780133976892
Author:
Paul J. Deitel, Harvey Deitel
Publisher:
PEARSON
Database Systems: Design, Implementation, & Manag…
Computer Science
ISBN:
9781337627900
Author:
Carlos Coronel, Steven Morris
Publisher:
Cengage Learning
Programmable Logic Controllers
Computer Science
ISBN:
9780073373843
Author:
Frank D. Petruzella
Publisher:
McGraw-Hill Education