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

It service support within the itil framework, Problem (a) IT Service Suppo...

Problem (a) IT Service Support within the ITIL framework is divided in a number of processes. Compare and contrast the following processes: i. Incident Management and Problem M

Emerging threats related to use of networks, Question requires you to submi...

Question requires you to submit a proposal based on the research report topic you will be addressing in the second assignment.  Note:  before commencing research on the topic, y

Important network security services, Question: (a) Consider that you en...

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

Describe phishing attacks, QUESTION (a) (i) Describe Phishing attacks. ...

QUESTION (a) (i) Describe Phishing attacks. (ii) Distinguish between Phishing and Spear Phishing attacks. (b) Describe two instances where an attacker sniffing on a netwo

Explain the term virtual private network, Question: (a) Besides privac...

Question: (a) Besides privacy, what other security functions does Pretty Good Privacy (PGP) provides? (b) What is the Post Office Protocol (POP) used for? Why is it impo

Explain the random key distribution, Q. Explain the random key distribution...

Q. Explain the random key distribution? The triple key management mechanisms ensure a better and complete security solution using the random key distribution mechanism. In this

Compare and contrast the trust models-pgp, a. PKI and PGP are two methods f...

a. PKI and PGP are two methods for generating and managing public keys for use in protocols such as secure email. Compare and contrast the trust models for public keys used in PKI

ISDN, Explain the architecture of ISDN.....?

Explain the architecture of ISDN.....?

Uc, every time i connect to WIFI the UC goes directly to 100% then i doesn'...

every time i connect to WIFI the UC goes directly to 100% then i doesn''t want to come down. what shall i do ?

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