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

Introduction to security and personnel, INTRODUCTION TO SECURITY AND PERSON...

INTRODUCTION TO SECURITY AND PERSONNEL When implementing information security, there are several human resource issues that should be addressed. They are •    Positioning and n

Simplex data exchange, Simplex data exchange Simplex communication def...

Simplex data exchange Simplex communication defines to communication that happens in one direction only. Two definitions have made over time: a common definition, which is des

Information security policy practices and standards, INFORMATION SECURITY P...

INFORMATION SECURITY POLICY PRACTICES AND STANDARDS Management from all the communities of interest should consider policies as basis for all information security efforts. Polic

What do you understand by environmental accounting, Question : Environm...

Question : Environmental Accounting is a means for businesses to fulfill their responsibilities for accountability to stakeholders. (a) What do you understand by Environment

Cyber security - vulnerabilities, The world has to deal with newly released...

The world has to deal with newly released vulnerabilities on a daily basis.  These vulnerabilities eventually lead to active exploits of systems, and it is our job as cyber securit

Negative cycle algorithm in minimum cost flows, QUESTION: (a) Show the...

QUESTION: (a) Show the Negative Cycle Algorithm in Minimum Cost Flows. (b) List the steps added in finding a Negative Cycle. (c) Apply Dijkstra's algorithm on the subs

Different architectures for wireless networks, (a) What are the different a...

(a) What are the different architectures for wireless networks? (b) Explain how WEP authentication and encryption works, describe the vulnerability. (c) In what ways are secu

Describe the process of components identification, Probelm 1: Give the ...

Probelm 1: Give the History and Evolution of Wireless Communication System. Complete explanation Probelm 2: Describe the process of Components Identification and cal

Introduction to physical security, INTRODUCTION TO PHYSICAL SECURITY The...

INTRODUCTION TO PHYSICAL SECURITY The Physical security addresses design, execution, and maintenance of countermeasures which protect physical resources of an organization. The

Cost benefit analysis (cba)-information security, Cost Benefit Analysis (CB...

Cost Benefit Analysis (CBA) The common approach for information security controls is economic feasibility of implementation. CBA is begun by evaluating the worth of assets which

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