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

Explain the concept of zero knowledge proofs, (a) Describe the concept of ...

(a) Describe the concept of zero knowledge proofs. Give a practical example. (b) Explain how a one way hash function works. (c) What are message authentication codes? (d)

Star topology, In Star topology all computers are connected using a cen...

In Star topology all computers are connected using a central device known as hub. Star networks are one of the most general computer network topologies. In its simplest way, a

TCP/ ip, Q1 (15 marks, 5 marks each part): This question has three parts: ...

Q1 (15 marks, 5 marks each part): This question has three parts: In a short paragraph (200-300 words) explain the fundamentals of Packet Switching and how it works. In a short pa

Types of errors detection in crc , CRC can detect the following errors bett...

CRC can detect the following errors better than check sums. a) Vertical errors b) Burst errors a) VERTICAL ERRORS:  This kind of error happens due to a hardware fai

Does ssl protect against eavesdropping, QUESTION (a) Consider the follo...

QUESTION (a) Consider the following authentication options A. Using password B. Using pin and fingerprint Which option A or B provides stronger security and why? (b

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

Cost accounting, ?Examples should include direct costs items, indirect cost...

?Examples should include direct costs items, indirect costs items, as well as variable costing. ?What are at least 5 types of expenses that are associated with manufacturing the

Marketing, what are the participant of marketing channal?

what are the participant of marketing channal?

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

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