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

Miss, You are an IT Security administrator in a banking organization. Your ...

You are an IT Security administrator in a banking organization. Your organization hired an outside IT firm to do a proof of Concept for new equipment which is a computer based syst

Risk determination, Risk Determination For purpose of relative risk asse...

Risk Determination For purpose of relative risk assessment, risk equals probability of vulnerability occurrence TIMES value MINUS percentage risk already controlled PLUS an elem

Deploying host-based idss, Deploying Host-Based IDSs -Proper implementat...

Deploying Host-Based IDSs -Proper implementation of HIDSs can be painstaking and time-consuming task .The process of deployment begins with implementing most critical systems fi

Professional issues in information technology, Thinking ethically is diffic...

Thinking ethically is difficult without a background in moral philosophy. Asking people to embrace ethics without offering practical explanation of the efficacy of so doing, is a t

Routing tables and address masks, ROUTING TABLES AND ADDRESS MASKS Add...

ROUTING TABLES AND ADDRESS MASKS Additional information is saved in routing table. Destination is kept as network address. Next hop is saved as IP address of router. Address m

What do you meant by the term bastion host, Question : (a) What do you...

Question : (a) What do you meant by the term "Bastion Host"? What is its use? (b) "Hostile" Java applets will do undesirable actions. Mention two problems caused by Hosti

Html, how to link html with a data base

how to link html with a data base

Internet protocol(ip), Internet Protocol IP Gives computer-to-comp...

Internet Protocol IP Gives computer-to-computer communication. Host and receiver addresses are computers. This is also known machine-to-machine communication.

Network security course work, doing coursework in Network Security to prese...

doing coursework in Network Security to present a possible solution to the problem at hand by creating a prototype of the new network security infrastructure. This new design shou

Use the chinese remainder theorem to evaluate x, Use the Chinese remainder ...

Use the Chinese remainder theorem to evaluate x from the following simultaneous congruences: x ≡ 1 (mod 2); x ≡ 2 (mod 3); x ≡ 3 (mod 5). Calculate gcd(14526, 2568). (

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