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

Difference between flow control and congestion control, (a) Describe briefl...

(a) Describe briefly the difference between flow control and congestion control in relation to a connection-oriented protocol such as TCP. (b)  What is the initial rate of data

Unguided media, Unguided Media This is the wireless media that transfe...

Unguided Media This is the wireless media that transfer electromagnetic waves without using a physical media. Waves are broadcast through the air. This is performing through r

Security protocol, which security protocols are predominantly used in web-b...

which security protocols are predominantly used in web-based e-commerce

Network protocol hierarchy , This assignment aims to enhance students' unde...

This assignment aims to enhance students' understanding of the network protocol hierarchy and flow control and error control techniques by implementing a sliding window protocol in

Ucsf medical center case study-information security, Example : UCSF Medical...

Example : UCSF Medical Center In the year 2002, the University of California, San Francisco (UCSF) Medical Center received an email message from someone who claimed to be a doct

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

Introduction to network protocol, In this assignment, you are required to e...

In this assignment, you are required to emulate the operation of a link layer and network layer protocols in a small computer network. Your program should behave like a single node

Compare the suitability and properties of isdn and adsl, Question : An a...

Question : An aircraft manufacturing company is considering linking the network of one of its offices to the network of its Headquarter using either xDSL or ISDN. i. Compare

What are the intermediate systems and how they work, Question: a) Expla...

Question: a) Explain what the following intermediate systems are and how they work? i. Repeater ii. Bridge b) A service is formally specified by a set of primitives (op

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