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

Arrangement of self-learning switches, QUESTION a) Consider the speed ...

QUESTION a) Consider the speed of propagation of an electrical signal is same to 2x10 8 m/s, evaluate the ratio of the propagation delay to the transmit time for the given typ

Risk control strategies-, Risk Control Strategies Once the ranked vulner...

Risk Control Strategies Once the ranked vulnerability risk worksheet has created, they should choose one of following 4 strategies to control each risk: •Apply safeguards which

Network security keys, The three primary types of network protection are th...

The three primary types of network protection are the same as the three primary areas where a network can be attacked. Every network needs protection against people-related, hardwa

Network management, Ask question #MinimAn NMS is connected to a remote netw...

Ask question #MinimAn NMS is connected to a remote network by a 64 Kb/s link. The network elements in the remote network generate 50 faults/second. Of these, 5% are critical and th

Sequential label and supply, What questions should Iris ask Charlie about t...

What questions should Iris ask Charlie about the new job, about Kelvin''s team, and about the future of the company?

Calculate euler totient function value, (a) Explain the importance of the ...

(a) Explain the importance of the Euler Totient function in Cryptography. Calculate Euler Totient function value, φ(1280). (b) Explain the role of the Authentication Server (

Calculate alpha and beta value caesar cipher, Task 1 a. Consider the t...

Task 1 a. Consider the table showing the relative frequencies of letters in English. Arrange the frequencies from largest to smallest, and make a cumulative plot, using Exc

Placeholders for the plaintext characters, Encode the following plaintext, ...

Encode the following plaintext, using the Caesar cipher:             LORD OF THE RINGS b) The following ciphertext              jw njbh lxmn cx kanjt has been encoded usi

Explain the main stages in the penetration testing process, Question: (...

Question: (a) i. Explain what is meant by Discretionary Access Control and Mandatory Access Control ii. Which method would be the most effective to ensure that users do

What are the intermediate systems and how they work, Question: a) Expla...

Question: a) Explain what the following intermediate systems are and how they work? i. Repeater ii. Bridge b) A service is formally specified by a set of primitives (op

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