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

Legal, LEGAL, ETHICAL AND PROFESSIONAL ISSUES To minimize liabilities an...

LEGAL, ETHICAL AND PROFESSIONAL ISSUES To minimize liabilities and reduce risks, information security practitioner should: •    to understand current legal environment •    to s

Base lining-risk management, Base lining •    Organizations do not have ...

Base lining •    Organizations do not have any contact to each other •    No two organizations are identical to each other •    The best practices are a moving target •    K

Packet filtering firewall-dynamic packet filtering, Dynamic Packet Filterin...

Dynamic Packet Filtering Dynamic Packet Filtering is also referred to as stateful firewalling. Here the firewall maintains the status of connections as well. When a connection

Complexity of network systems, Computer networks is a complex subject due t...

Computer networks is a complex subject due to the given reasons: MANY DIFFERENT TECHNOLOGIES EXIST: The first reason for the complexity of networks is that there are s

Intrusion detection and classification, i want to detec and classify networ...

i want to detec and classify network anomaly detection based on KDD99 data set using swarm intelligence

Risk control strategies-risk management, Risk Control Strategies Once th...

Risk Control Strategies Once the ranked vulnerability risk worksheet has created, they should choose one of following 4 strategies to control each risk: •    Apply safeguards wh

Growth of lan technology, GROWTH OF LAN TECHNOLOGY The production of s...

GROWTH OF LAN TECHNOLOGY The production of shared communication channels (LANs) started in 1960s and early 1970. The basic idea behind was to reduce the number of connectio

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

What is information-information security, What is information Informatio...

What is information Information comprises the meanings and interpretations which people place upon the facts, or data. The value of information springs from the ways it can be i

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