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

Draw the waveform for an asynchronous transmission, (a) Draw the waveform ...

(a) Draw the waveform for an asynchronous transmission with the given specifications: 8 data bits with value 11010001 (LSB listed first here), one parity bit (even), one star

RESPONSE, Dropbox’s tool shows how chatbots could be future of cybersecurit...

Dropbox’s tool shows how chatbots could be future of cybersecurity

Computer security incident response team, QUESTION 1 Using a real life ...

QUESTION 1 Using a real life scenario or context list and set the scene for at least four advantages that an organized incident response program promotes. QUESTION 2 Yo

Legal, LEGAL, ETHICAL AND PROFESSIONAL ISSUES To minimize liabilities an...

LEGAL, ETHICAL AND PROFESSIONAL ISSUES To minimize liabilities and reduce risks, information security practitioner should: •    to understand current legal environment •    to s

Describe briefly an artificial intelligent technique, Question : (a) W...

Question : (a) What is an IDS and what is the basic problem it faces which can be solved by Artificial Intelligence. (b) Identify and describe briefly an Artificial Intell

Packet sniffers, PACKET SNIFFERS A packet network protocol analyzer is a...

PACKET SNIFFERS A packet network protocol analyzer is a network tool which collects copies of packets from network and analyzes them. It can give network administrator with valu

Explain characteristics of associative memory networks, (a) Describe the pr...

(a) Describe the principal characteristics of associative memory networks? (b) Name the two basic types of associative memories and the differences between them. (c) Give an

Different architectures for wireless networks, (a) What are the different a...

(a) What are the different architectures for wireless networks? (b) Explain how WEP authentication and encryption works, describe the vulnerability. (c) In what ways are secu

Potential risks to information systems, Information System Security 1. ...

Information System Security 1. Write about: a. Potential Risks to Information Systems b. Factors to be addressed for making information systems more secure 2. Write about t

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