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

Project, Network diagram for a mediacal care

Network diagram for a mediacal care

What is authentication? explain authentication protocols, What is Authentic...

What is Authentication/confirmation?  How it is different from  the Authorization/approval?  Explain in brief different authentication protocols along with their merits and demerit

Pgp encryption, Produce a short report of your experiences in installing an...

Produce a short report of your experiences in installing and using PGP. The report should be written in the form of a journal that contains at least the following items: A de

Risk identification-information security, Risk Identification Risk manag...

Risk Identification Risk management comprises of identifying, classifying and prioritizing organization’s information assets, threats and vulnerabilities also. Risk Identificati

What standards are to be applied, Government funding has been given to a un...

Government funding has been given to a university consortium establishing a repository of resources for school teachers. They have engaged you to develop a search facility for teac

Wan architecture and wan service, MegaCorp INC. is a large manufacturing f...

MegaCorp INC. is a large manufacturing firm that operates 5 factories in Dallas, 4  factories in Los Angeles, and 5 factories in Albany, New York.  It operates a tightly  connected

Selecting a risk control strategy, Selecting a Risk Control Strategy Risk...

Selecting a Risk Control Strategy Risk controls involve selecting one of the 4 risk control strategies for every vulnerability. The flowchart is shown in the figure given below

Securities Issues in a company, 'Near Field Communication' (NFC) technologi...

'Near Field Communication' (NFC) technologies are expected to become commonplace in the near future. Some relevant features are these: A suitable device (such as a mobile pho

Kasonet pinging system, KASONet Pinging System: Project Title:       ...

KASONet Pinging System: Project Title:                                                           "KASONet Pinging System"   Brief Overview of Project: The o

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