User Account

All Pages

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

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

Improving domain blacklisting - spam mail, Improving domain blacklisting: ...

Improving domain blacklisting: Current domain blacklisting techniques are not very effective as spammers keep replacing blacklisted domains with newly registered domains. Also

Otway-Rees Key Exchange Protocol, Code to implement Otway-Rees Key Exchang...

Code to implement Otway-Rees Key Exchange Protocol

Direct sequence modulation, Question 1 a) Provide three advantages of ...

Question 1 a) Provide three advantages of using optical fiber. b) Distinguish between "Direct Sequence Modulation" and "Frequency Hopping" c) Decribe the purpose of using "

CNSS Security model, "Using the CNSS Model, examine each of the cells and w...

"Using the CNSS Model, examine each of the cells and write a brief statement on how you would address the components respesented in that cell"

People, People,Procedures,Data Asset Identification-Risk Management Th...

People,Procedures,Data Asset Identification-Risk Management The human resources, data information and documentation assets are more difficult to identify. People having knowle

Address resolution protocol (arp), ADDRESS RESOLUTION PROTOCOL (ARP) T...

ADDRESS RESOLUTION PROTOCOL (ARP) TCP/IP can use any of the three address resolution functions relaying on the addressing procedure used by the underlying hardware. To guarant

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

Briefly explain the contents of the needs analysis, QUESTION (a) Brief...

QUESTION (a) Briefly explain the contents of the Needs Analysis, which is step in the process of network design. (b) Describe on the three ways of improving the performan

Crytography, attacks on crytography

attacks on crytography

Write Your Message!

Captcha
Order Assignment

Featured Services

Order Now

Popular Subjects

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!

Submit Assignment

Academics

Major Subjects

Majors

Get In Touch

whatsapp: +91-977-207-8620

Phone: +91-977-207-8620

Email: [email protected]

TERMS & POLICIES

HELP & SUPPORT

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd