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

Describe how ipsec provides data source authentication, Question: (a) ...

Question: (a) Describe how IPSec provides data source authentication. (b) Which protocol can be used to provide limited traffic analysis confidentiality? Why is it "limite

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

Lan topologies, Network can be distinguished by shape. According to which t...

Network can be distinguished by shape. According to which there are three most popular methodologies, which are shown as follows; Star Ring Bus

Perimeter Network Security System coursework, what is the guaranteed qualit...

what is the guaranteed quality of this coursework? how many days it take for 10-12 pages? how much will be? thanks

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

Digital signature, A digital signature is a stamp on the data, which is uni...

A digital signature is a stamp on the data, which is unique and very hard to forge.  A digital signature has 2 steps and creates 2 things from the security perspective. STEP 1

What is the main security vulnerability of ipv4, Question: (a) What is...

Question: (a) What is the main security vulnerability of IPv4? (b) Which protocol can be used for secure remote login? (c) Distinguish between the transport and tunnel

Quote, How much would it cost to have a project completed by tomorrow night...

How much would it cost to have a project completed by tomorrow night?

Marketing, what are the participant of marketing channal?

what are the participant of marketing channal?

Write pseudocode for the password guessing algorithm, Write Pseudocode for ...

Write Pseudocode for the password guessing algorithm: Consider the following authentication protocol: Client Transmission Host

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