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

Imap and pop functions, How does the POP functions? What are the advantages...

How does the POP functions? What are the advantages/benefits of IMAP over POP? POP stands for Post Office Protocol, version 3 (POP3) is one of the easiest message access protoc

Miss, You are an IT Security administrator in a banking organization. Your ...

You are an IT Security administrator in a banking organization. Your organization hired an outside IT firm to do a proof of Concept for new equipment which is a computer based syst

What is border gateway protocol, Border Gateway Protocol It is a proto...

Border Gateway Protocol It is a protocol needed to advertise the set of networks that can be achieved within an autonomous machine. BGP activates this information to be shared

Evaluations, Evaluations, Assessment, and Maintenance of Risk Controls W...

Evaluations, Assessment, and Maintenance of Risk Controls When the control strategy has been implemented, it should be monitored and measured on an ongoing basis to determine ef

Name the various layers of the osi model, Problem (a) Name the various ...

Problem (a) Name the various layers of the OSI model. (b) Show, by means of a diagram, how  the TCP/IP  reference model  is different from the OSI-7 reference model? Why is

The security systems development life cycle (secsdlc), The Security Systems...

The Security Systems Development Life Cycle (SecSDLC) The same phases which is used in traditional SDLC can be adapted to support specialized implementation of IS project,At its

Threads and attacks-information security, THREADS AND ATTACKS Threat is ...

THREADS AND ATTACKS Threat is an object, person, or other entity which represents a constant danger to an asset. To make sound decisions about information security, management s

Semester 2, Do you have assignment solutions for CCE UPES MBA for oil and g...

Do you have assignment solutions for CCE UPES MBA for oil and gas semester 2

Introduction to security and personnel, INTRODUCTION TO SECURITY AND PERSON...

INTRODUCTION TO SECURITY AND PERSONNEL When implementing information security, there are several human resource issues that should be addressed. They are •    Positioning and n

Find the capacity of the wcdma, Question: (a) Describe the term interfe...

Question: (a) Describe the term interference in the space, time, frequency, and code domain. (b) Consider a 1 G - AMPS: 824-849 MHz (forward) ; 869-894 MHz (reverse). B

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