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

Ethical hacking penetration testing, Get a copy of Metasploitable at Make...

Get a copy of Metasploitable at Make">http://sourceforge.net/projects/metasploitable/files/Metasploitable2/ Make sure to follow these directions very carefully. You will get po

Explain the close procurement project process, Question 1: Why do we ne...

Question 1: Why do we need a Law of Contract? a Explanation Reasons to have a law of contract b Explain the close procurement project process - Explanation (causes,

Locality of reference , LOCALITY OF REFERENCE PRINCIPLE:  Principle of...

LOCALITY OF REFERENCE PRINCIPLE:  Principle of "Locality of Reference" use to predict computer interaction patterns. There are two patterns shown as follows: a) Spatial loca

Important features of application layer, Describe the important features of...

Describe the important features of application layer. The features of the application layer are as follows. 1. Efficient User Interface Design is explained below: Appli

Explain about structure of management information, Question 1 a) What is a...

Question 1 a) What is a NMS? Question 2 Explain about Structure of Management Information Question 3 A)In which UDP port number does a protocol entity receive message?

Produce a pcap file from a wireshark capture, Question requires you to prod...

Question requires you to produce a pcap file from a Wireshark capture.  In addition, you must include a screen capture of Wireshark and some specific information regarding the fram

Explain the schemes for distribution of public keys, (a) What is a pseudora...

(a) What is a pseudorandom generator? Give an example describing how it works. (b) Explain the key components of a wireless network and their purpose. (c) Describe the authen

Define parity bit, PARITY BIT: A parity bit is an extra bit transmitt...

PARITY BIT: A parity bit is an extra bit transmitted with data item select to give the resulting bit odd or even parity. For example an even parity data packet 10100001 has p

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

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