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

What is network virtual terminal, Network Virtual Terminal It is a set...

Network Virtual Terminal It is a set of principles describing a very simple virtual terminal interaction. The NVT is needed in the start of a Telnet session. Communication wit

Social studies, how would land elevation have canged if coronado had travel...

how would land elevation have canged if coronado had traveled 150 miles due west from what is today arizona instead of west toward new mexico

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

Fragment identification, FRAGMENT IDENTIFICATION: IDENT field in every...

FRAGMENT IDENTIFICATION: IDENT field in every fragment matches IDENT field in real datagram. Fragments from different datagrams may arrive out of order and still be saved out.

Ipv6 next header, IPV6 NEXT HEADER It is given in the figure below:

IPV6 NEXT HEADER It is given in the figure below:

What is information-information security, What is information Informatio...

What is information Information comprises the meanings and interpretations which people place upon the facts, or data. The value of information springs from the ways it can be i

Explain the operation of the matchmaker middle agent, Question 1: (a) E...

Question 1: (a) Explain the operation of the "matchmaker" middle agent. (b) Describe why broker middle agents are more efficient in terms of the time taken for a service to

E-commerce, briefly expslain type of e-commerce

briefly expslain type of e-commerce

Spambot detection - spam mail, Spambot Detection: The  previous studie...

Spambot Detection: The  previous studies in this field  have focused on content and meta-content based features.  The main assumption in this area of spam detection of late is

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