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 do you understand by the term integrity, Question: (a) What do yo...

Question: (a) What do you understand by the term "integrity"? (b) Which type of attack denies authorized users access to network resources? (c) You have discovered tha

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

Plain-text using play-fair encryption, What is one-time pad for encryp...

What is one-time pad for encryption?  Describe how it offers both Confusion and Diffusion. Using the letter encoding discussed in class (along with one-time

Udp datagram format, UDP DATAGRAM FORMAT: It is given in the figure be...

UDP DATAGRAM FORMAT: It is given in the figure below:

Softbank theft of consumer data -information security, Example : Softbank –...

Example : Softbank – theft of consumer data for extortion Softbank of Japan offers broadband Internet services across Japan through 2 subsidiaries – Yahoo! BB and Softbank BB. I

Point-to-point topology, POINT-TO-POINT: In Point-to-Point topology th...

POINT-TO-POINT: In Point-to-Point topology there are two kind of topologies. 1) STAR topology 2) TREE topology In star topology each and every computer is connect

Selecting a risk control strategy, Selecting a Risk Control Strategy Risk...

Selecting a Risk Control Strategy Risk controls involve selecting one of the 4 risk control strategies for every vulnerability. The flowchart is shown in the figure given below

CS, Discuss how developers should apply the following countermeasures to im...

Discuss how developers should apply the following countermeasures to improve the security of their code:

Develop a tcp-based client-server socket program, Develop a TCP-based clien...

Develop a TCP-based client-server socket program for transferring a large message. The message transmitted from the client to server is read from a large file (size is about 30000

Ipv6 addressing, IPv6 ADDRESSING IPv6 has 128-bit addresses. A 128-bit...

IPv6 ADDRESSING IPv6 has 128-bit addresses. A 128-bit address adds network prefix and host suffix. An benefit of IPv6 addressing is that there is address classes i.e. prefix/s

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