ciphertext, Computer Network Security

Assignment Help:
Encode the following plaintext, using the Caesar cipher:

LORD OF THE RINGS
b) The following ciphertext

jw njbh lxmn cx kanjt

has been encoded using a generalised Caesar cipher where the following rule computes a character ci in the cipher text from a character pi in the plain text:

ci = E(pi) = pi + d

where d is a positive integer.

Find the number d and the plain text. Hint: use a table of English letter frequencies. This information can be found on the Internet.

c) Now consider the following cipher text:

homlox prv hetorx orxolxpersorx

A more general substitution cipher has been used. Recall that this means that every letter of the alphabet appearing in the plain text is replaced with another unique letter of the alphabet. For example, the letter ''a'' could be mapped into ''h'', the letter ''b'' into ''x'' etc. The ciphertext then simply consists of these mapped letters.
Work out the original plain text message, using the following approach:

(i) Write a line of dashes ("_") as placeholders for the plaintext characters corresponding to each letter in the above cipher text. Make sure you also mark the spaces between the different words as they will give you clues as soon as you know some of the letters.

(ii) Using the English letter frequency table, find the letter which the letter "e" is most likely to be replaced with. Use this to replace some of the "_" by the letter "e" (simply copy the last line you wrote and then replace).

Related Discussions:- ciphertext

Digital certificates, A Certificate presents an organization in an official...

A Certificate presents an organization in an official digital form. This is same to an electronic identity card which serves the purpose of Identifying the owner of the certificate

Ip datagrams, on LAN,where are IP datagrams transported?

on LAN,where are IP datagrams transported?

Pinging a web server, Ask quIf you are pinging a web server from a user’s c...

Ask quIf you are pinging a web server from a user’s client PC, how might the statistical information provided by ping be useful to you?estion #Minimum 100 words accepted#

Describe the five-layer network using block diagrams, Problem 1: a) One...

Problem 1: a) One of the limitations of file processing systems is data inconsistency. Briefly explain with the help of an example what do you understand by this phrase. b)

Semester 2, Do you have assignment solutions for CCE UPES MBA for oil and g...

Do you have assignment solutions for CCE UPES MBA for oil and gas semester 2

Introduction to planning for security, INTRODUCTION TO PLANNING FOR SECURIT...

INTRODUCTION TO PLANNING FOR SECURITY The creation of an information security program begins with creation and review of organization’s information security policies, standards,

Differentiate between private key and public key encryption, Problem (...

Problem (a) Differentiate between private key and public key encryption. (b) What issue with private key encryption is resolved with public key encryption? (c) Describe

Limitations of firewall, Limitations of firewall Firewalls cannot prote...

Limitations of firewall Firewalls cannot protect a network if security rules are not followed properly by an organization or if the rules are not defined properly. Firewalls ar

Functional areas in network management, Question 1 a) Explain how CSMA...

Question 1 a) Explain how CSMA/CD works. b) Describe the term "exponential back-off". c) Describe the differences between "circuit switching" and "packet switching". d) Th

Cyber security, How to pretect my computer from attacking

How to pretect my computer from attacking

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd