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

Mention most relevant clause of iso 27001:2005, QUESTION (In this ques...

QUESTION (In this question, you will need to use the ISO 27001:2005 and ISO 27002:2005 standards) For each of the situations below, comment on the following: 1. Mention

routing information exchange and bellman-ford algorithm, You are free to d...

You are free to design the format and structure of the routing table kept locally by each node and exchanged among neighboring nodes. 1. Upon the activation of the program, each

Define packet, CONCEPT OF PACKET : Network systems splits data in small ...

CONCEPT OF PACKET : Network systems splits data in small junks or blocks known as packets, which they send individually. Why we required packets rather than bits? The answer to

Cyber security, How to pretect my computer from attacking

How to pretect my computer from attacking

Define network, A Network is described as a system for connecting compu...

A Network is described as a system for connecting computers using a single transmission technology. The computers can interact with each other in a network. They can receive an

Ip address, How to find an ip address?

How to find an ip address?

Explain web defacement, QUESTION (a) Compare and contrast phishing and ...

QUESTION (a) Compare and contrast phishing and pharming attacks (b) Nowadays, web defacement may not always be visual (i) Explain web defacement (ii) What is the main

Characteristics of radial basis function neural networks, Problem : (a)...

Problem : (a) Provide one possible classification of PCA, ART, RBF, and Fuzzy ARTMAP networks. (b) Describe in detail the characteristics of Radial Basis Function Neural Net

Point to point transmission(ppp), Normal 0 false false fals...

Normal 0 false false false EN-US X-NONE X-NONE

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

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