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

Explain how the framework will align to the model, MB Enterprise Systems Lt...

MB Enterprise Systems Ltd based in Mauritius is a company specialized in application development with Europe as the main customer base. The company has implemented CMMI and has rec

Describe how a cellular network works, Problem 1 . Show various features of...

Problem 1 . Show various features of a 1G network Total three features for each feature of 1G Problem 2. Describe how a cellular network works with functional block diagram

Rsa block and vernam stream ciphers, RSA Block and Vernam Stream Ciphers ...

RSA Block and Vernam Stream Ciphers This assignment involves writing two small Python scripts and a report. Before you start you must download the ?le summarysheets.zip from th

Systems development life cycle security-information security, The Role of t...

The Role of the Investigation The first phase, investigation is the most significant. What problem is the system being developed to solve? During investigation phase, objectives

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

Explain the term quality of service in networks, QUESTION (a) One of th...

QUESTION (a) One of the biggest drawbacks that GNS3 has is that it supports only the IOS images of routers. This means that users cannot emulate Cisco switches. Suggest two sol

Transmission errors in networking, TRANSMISSION ERRORS:  Transmission...

TRANSMISSION ERRORS:  Transmission exceptions may happen due to different causes for example power surges or interference may delete data during transmission. In result of wh

Computer security, Assume that the RSA problem is hard, prove that the RSA ...

Assume that the RSA problem is hard, prove that the RSA encryption is secure against IND- CPA. Provide a game between an adversary A and a simulator (or challenger) B.

Algorithm, algorithm on simple intrest

algorithm on simple intrest

Project, project on ensuring data securities on cloud computing

project on ensuring data securities on cloud computing

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