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

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

Project, Network diagram for a mediacal care

Network diagram for a mediacal care

Marketing, what are the participant of marketing channal?

what are the participant of marketing channal?

Enterprise information security policy (eisp), Enterprise Information Secur...

Enterprise Information Security Policy (EISP) EISP also known as security policy directly supports the mission of the organization and sets the strategic direction, scope, and t

Backup, types of firewall and backup

types of firewall and backup

Packets and frames, PACKETS: Packet is a generic word that define to sma...

PACKETS: Packet is a generic word that define to small code of data. Packet have different format. Each hardware needs different packet format.  FRAME: A hardware frame or

Address masks, ADDRESS MASKS To identify receiver, network apply addre...

ADDRESS MASKS To identify receiver, network apply address mask to receiver address and calculate to network address in routing table. It can use Boolean 'and' to calculate the

Identified issues in networks, The "Big Red Rocks" (BRR) mining company is ...

The "Big Red Rocks" (BRR) mining company is based and operates in Western Australia. They are primarily an iron ore miner, but they also produce electricity through tidal power to

CNSS, Assume that a security model is needed for the protection of informat...

Assume that a security model is needed for the protection of information in your class. Using the CNSS model, examine each of the cells and write a brief statement on how you would

Http request message, Question (a) Consider that you enter the subsequent ...

Question (a) Consider that you enter the subsequent URL in the address bar of a popular web client and that both the server and client accepts HTTP version 1.1. i. What can be

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