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

Implement security measures, Problem (a) Give two reasons for companie...

Problem (a) Give two reasons for companies to implement security measures. (b) What is the regulatory expectation regarding i. healthcare information, ii. financial

Systems development life cycle security-information security, The Role of t...

The Role of the Investigation The first phase, investigation is the most significant. What problem is the system being developed to solve? During investigation phase, objectives

Application-based ids, Application-Based IDS Application-based IDS (AppI...

Application-Based IDS Application-based IDS (AppIDS) is an advanced version of HIDS. It examines application for abnormal events. The ability to view encrypted data is the uniqu

Management of classified data-risk management, Management of Classified Dat...

Management of Classified Data Management of classified data comprises of its storage, distribution, portability, and destruction of classified data. All information which is not

Develop a tcp-based client-server socket program, Develop a TCP-based clien...

Develop a TCP-based client-server socket program for transferring a large message. The message transmitted from the client to server is read from a large file (size is about 30000

Point to point transmission(ppp), Normal 0 false false fals...

Normal 0 false false false EN-US X-NONE X-NONE

Calculate the total latency, Question (a) Inspect the following ifconfi...

Question (a) Inspect the following ifconfig output of an IPv6 interface: i. What is the hidden Hardware Address of the interface on Line #1? ii. What is the hidden subn

Linux, Discuss the risks of having a single root user

Discuss the risks of having a single root user

Difference between synchronous tdm and statistical tdm, Question (a) A CRC...

Question (a) A CRC is constructed to generate a 4-bit FCS for an 11-bit message. The divisor polynomial is X 4 + X 3 + 1 (i) Encode the data bit sequence 00111011001 using po

Provide the network configuration, QUESTION: a) Below is a capture of a...

QUESTION: a) Below is a capture of an Ethernet II frame which has an IPv4 packet and a segment. Provide the source MAC address in hexadecimal; the source IP address, the length

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