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

RESPONSE, Dropbox’s tool shows how chatbots could be future of cybersecurit...

Dropbox’s tool shows how chatbots could be future of cybersecurity

Efforts of advanced research project agency, ADVANCED RESEARCH PROJECT AGEN...

ADVANCED RESEARCH PROJECT AGENCY (ARPA) The efforts of ARPA was to active all its research groups have accept to new era computers. For this purpose ARPA started investing in wa

Assignment, for making the assignment

for making the assignment

Attackers motives behind the cyber attack, Attacker's Motives behind the Cy...

Attacker's Motives behind the Cyber Attack Before adapting the necessary measures to deal with the problem, understanding and evaluating the blogger's psyche and his motivation

Symmetric encryption-cryptography, Symmetric Encryption This encryption ...

Symmetric Encryption This encryption method makes use of same “secret key” to encipher and decipher the message and it is termed as private key encryption. This type of encrypti

Media, what is guided media or unguided media

what is guided media or unguided media

Csma/ca, CSMA/CA Wireless needs collision avoid ness rather than colli...

CSMA/CA Wireless needs collision avoid ness rather than collision checking. Transmitting computer puts very short codes to receiver. Receiver responds with short message getti

Compare and contrast between block and stream ciphers, Problem 1 Solve ...

Problem 1 Solve the following Caesar cipher by showing your working: EM KIUM EM AIE EM KWVYCMZML Problem 2 Compare and contrast between block and stream ciphers, listin

Routers, Routers They transfer packets among multiple interconnected n...

Routers They transfer packets among multiple interconnected network machines (i.e. LANs of different kind). They perform in the data link, physical and network layers. They ha

Distinguish between passive and active attacks, Problem (a) Distinguis...

Problem (a) Distinguish between passive and active attacks. (b) Give two reasons why it is important to organise security awareness programs for users. (c) Describe how

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