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

Complexity of network systems, Computer networks is a complex subject due t...

Computer networks is a complex subject due to the given reasons: MANY DIFFERENT TECHNOLOGIES EXIST: The first reason for the complexity of networks is that there are s

Business needs-information security, BUSINESS NEEDS Information security...

BUSINESS NEEDS Information security performs four main functions for an organization. 1. Protects the ability of organization to function. 2. Enables safe operation of applicat

What is feedforward multilayer perceptron neural network, Question: (a)...

Question: (a) Explain and illustrate with a drawing the three-layer feedforward multilayer perceptron neural network. (b) Summarize the standard backpropagation algorithm in

Digital certificates, A Certificate presents an organization in an official...

A Certificate presents an organization in an official digital form. This is same to an electronic identity card which serves the purpose of Identifying the owner of the certificate

Keystroke-based access control model, Suppose you are working for one of th...

Suppose you are working for one of the leading credit reporting agencies that manages users' credit rating info with different financial institutions.  The company wishes to implem

Who are the individuals who cause these security problems, Who are the indi...

Who are the individuals who cause these security problems? Many unauthorized people who cause network security problems for obtaining information about the other users and causi

Ip datagrams, on LAN,where are IP datagrams transported?

on LAN,where are IP datagrams transported?

Reason for multiple topologies, REASON FOR MULTIPLE TOPOLOGIES Every t...

REASON FOR MULTIPLE TOPOLOGIES Every topology has disadvantages and advantages, which are described below: IN A RING:  It is simple to coordinate access to other dev

Packet filtering firewall-dynamic packet filtering, Dynamic Packet Filterin...

Dynamic Packet Filtering Dynamic Packet Filtering is also referred to as stateful firewalling. Here the firewall maintains the status of connections as well. When a connection

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