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

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

Maximum transmission unit (mtu), Maximum Transmission Unit  (MTU) Eac...

Maximum Transmission Unit  (MTU) Each hardware method specification adds the definition of the maximum size of the frame data area, which is known the Maximum Transmission Uni

Computer security, For this assessment, students must research and analyse ...

For this assessment, students must research and analyse two different scenarios. The two scenarios must be chosen from those described below and submitted as one Microsoft PowerPoi

Nstissc security model, NSTISSC SECURITY MODEL The NSTISSC Security Model ...

NSTISSC SECURITY MODEL The NSTISSC Security Model provides a detailed perspective on security. While the NSTISSC model covers the 3 dimensions of information security, it removes

Implement database security, Question: (a) Describe fully with example ...

Question: (a) Describe fully with example the two access control methods available to implement database security. (b) Discuss why database statistics (meta data) provide es

Security analysis-information security, SECURITY ANALYSIS Overview •    ...

SECURITY ANALYSIS Overview •    Know yourself: examine, identify, and understand the information and systems which are currently in place •    Know the enemy: examine, identify,

Who are the individuals who cause these security problems, Who are the indi...

Who are the individuals who cause these security problems? Many unauthorized people who cause network security problems for obtaining information about the other users and causi

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