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

Computer fundamentals, Ask You have been asked by a new client to assist i...

Ask You have been asked by a new client to assist in setting up a new computer for her coffee shop. She has just purchased the newest Apple computer from an online site. Should wou

Illustrate the term file carving, QUESTION (a) Illustrate the term fil...

QUESTION (a) Illustrate the term file carving. (b) What are the basic three main techniques for image steganography? (c) Distinguish between vector graphics and raster

Calculate the dynamic range of the 16-bit scanner, You are hired as a consu...

You are hired as a consultant to help design a digital library in which books are scanned and stored digitally and made available to users of the World Wide Web. Assume that the li

Business needs-information security, BUSINESS NEEDS Information security...

BUSINESS NEEDS Information security performs four main functions for an organization. 1. Protects the ability of organization to function. 2. Enables safe operation of applicat

Address masks, ADDRESS MASKS To identify receiver, network apply addre...

ADDRESS MASKS To identify receiver, network apply address mask to receiver address and calculate to network address in routing table. It can use Boolean 'and' to calculate the

CS, Discuss how developers should apply the following countermeasures to im...

Discuss how developers should apply the following countermeasures to improve the security of their code:

What is network address translation, Question: (a) What is Network Add...

Question: (a) What is Network Address Translation (NAT)? Why is it used? (b) Given a following information by your ISP about your newly acquired Frame Relay connection:

Evaluations, Evaluations, Assessment, and Maintenance of Risk Controls W...

Evaluations, Assessment, and Maintenance of Risk Controls When the control strategy has been implemented, it should be monitored and measured on an ongoing basis to determine ef

Object tracking using wireless sensor networks, This project involves the d...

This project involves the design and development of a simulation environment of many sensors tagging material/ machinery/equipment/etc in a warehouse site to help monitor and manag

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