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

Vulnerability identification-risk management, Vulnerability Identification ...

Vulnerability Identification Specific avenues threat agents can exploit to attack an information asset are known as vulnerabilities. Examine how each threat can be generated and

Wireless security tools, WIRELESS SECURITY TOOLS An organization which s...

WIRELESS SECURITY TOOLS An organization which spends its time securing wired network and leaves wireless networks to operate in any manner is opening itself up for security brea

Calculate the dynamic range of the 16-bit scanner, You are hired as a consu...

You are hired as a consultant to help design a digital library in which books are scanned and stored digitally and made available to users of the World Wide Web. Assume that the li

Explain major differences between wpa and wpa2, Question: Suppose the f...

Question: Suppose the following brief history of WLAN security standards: When the security of WEP was broken, the industry turned to the IEEE to fix it. The IEEE said it could

Explain the various costs of quality, Problem 1: Show what are the bene...

Problem 1: Show what are the benefits of project quality management? • Customer satisfaction • Reduced cost • Increased competitiveness • Fulfilment of social and economic r

Documenting the results of risk assessment, Documenting the Results of Risk...

Documenting the Results of Risk Assessment The goal of this process is to recognize the information assets, list them, and rank according to those most required protection. The

Encryption, How safe is the encryption of virtual private networks?

How safe is the encryption of virtual private networks?

How Ethical are Major Internet Companies?, Ask question #MHow Ethical are M...

Ask question #MHow Ethical are Major Internet Companies?

Differences between a hacker and a cracker, Question: (a) Which of the...

Question: (a) Which of the following is not a goal of security: i) detection ii) prevention iii) recovery iv) prosecution (b) You are an honest student. One day you

Calculate the rsa public and private keys, (a) Which PKI (Public Key Infra...

(a) Which PKI (Public Key Infrastructure) model is typically favored by business organization? (b) Give one possible use of the "extensions" field of an X.509 certificate

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