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

Access controls-information security, Access Controls Access controls ad...

Access Controls Access controls addresses admission of a user into a trusted area of organization. It comprises of a combination of policies & technologies. The ways to control

What is the size of the initialization vector n wpa, Question : Wi-Fi p...

Question : Wi-Fi protected access (WPA) was specified by the Wi-Fi alliance with the primary aim of enhancing the security of existing 802.11 networks. However, WPA was only a

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

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

Digital certificates-cryptography, Digital Certificates Digital Certific...

Digital Certificates Digital Certificates are electronic document having key value and identifying information about entity which controls key. Digital signature which is attach

Issue specific security policy, Why an organization need the issue specific...

Why an organization need the issue specific security policy

Principles of information security, The key concepts and frameworks covered...

The key concepts and frameworks covered in modules 1-4 are particularly relevant for this assignment. Assignment 2 relates to the specific course learning objectives 1, 2 and 3:

Summarises the firewall protocols, Your rules should ensure that Internet a...

Your rules should ensure that Internet access will be restricted to the following: Only the following services will be permitted as OUTBOUND traffic (to the Internet from the DM

Cyber security, How to pretect my computer from attacking

How to pretect my computer from attacking

Information and network security, Information and Network Security Part ...

Information and Network Security Part 1- Recovery of an encrypted `word' using a forward search attack. Complete and correct summary for part 1. Adequately commented, clea

Find the possible deciphering transformations, Question: (a) A string o...

Question: (a) A string of ciphertext was enciphered using an a±ne transformation of single letters in a 28-letter alphabet consisting of A to Z, a blank and a?, where A to Z ha

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