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

Unguided media, Unguided Media This is the wireless media that transfe...

Unguided Media This is the wireless media that transfer electromagnetic waves without using a physical media. Waves are broadcast through the air. This is performing through r

Asymmetric encryption-cryptography, Asymmetric Encryption Asymmetric encr...

Asymmetric Encryption Asymmetric encryption method makes use of two different but related keys and either key can be used to encrypt or decrypt the message. This method is freque

Routing protocol for a banking network, You have been asked to design a Ban...

You have been asked to design a Banking Network with two primary types of locations.  Branches that will have 3 subnets, one /25 subnet one /26 subnet for ABMS and one /26 s

Routing tables and address masks, ROUTING TABLES AND ADDRESS MASKS Add...

ROUTING TABLES AND ADDRESS MASKS Additional information is saved in routing table. Destination is kept as network address. Next hop is saved as IP address of router. Address m

Programming, For this assignment you will create a program called MMWordFix...

For this assignment you will create a program called MMWordFix (Multi-Mode WordFix). This program prompts the user to select one of three word filters (uppercase, lowercase, encryp

Find the services implemented on your computer, Question: (a) Which typ...

Question: (a) Which type of attacker represents the most likely and most damaging risk to your network? (b) What is the basic reason that social engineering attacks succeed?

Define network, A Network is described as a system for connecting compu...

A Network is described as a system for connecting computers using a single transmission technology. The computers can interact with each other in a network. They can receive an

Computer security incident response team, QUESTION 1 Using a real life ...

QUESTION 1 Using a real life scenario or context list and set the scene for at least four advantages that an organized incident response program promotes. QUESTION 2 Yo

Computer security, Implementing an effective online authentication scheme i...

Implementing an effective online authentication scheme in practice faces many challenges. Systems with highly sensitive data often require multifactor authentication. But, requirin

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