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

Military and space technology, crack the secret message and explain how the...

crack the secret message and explain how the code works. The clue is that it has something to do with the computer keyboard. J-Q-H-6 Q-E-F-Q-H-D-3-W 8-H 5-Y-3 7-W-3 9-R--D-9-J

What is network address translation, Question: (a) What is Network Add...

Question: (a) What is Network Address Translation (NAT)? Why is it used? (b) Given a following information by your ISP about your newly acquired Frame Relay connection:

Explain the purpose of the dr and bdr, QUESTION a) Compare and contras...

QUESTION a) Compare and contrast between static and dynamic routing. b) What are the merits (five merits) and limitations (3 limitations) of using Open Shortest Path First

Threads and attacks-information security, THREADS AND ATTACKS Threat is ...

THREADS AND ATTACKS Threat is an object, person, or other entity which represents a constant danger to an asset. To make sound decisions about information security, management s

Security and basics steps in writing thesis, how can i start thesis? Please...

how can i start thesis? Please mention so of examples?

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

Network, what is computer network?

what is computer network?

Security policies, implementing password policy in organisation

implementing password policy in organisation

Risk identification-information security, Risk Identification Risk manag...

Risk Identification Risk management comprises of identifying, classifying and prioritizing organization’s information assets, threats and vulnerabilities also. Risk Identificati

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