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

Different architectures for wireless networks, (a) What are the different a...

(a) What are the different architectures for wireless networks? (b) Explain how WEP authentication and encryption works, describe the vulnerability. (c) In what ways are secu

Limitations of firewall, Limitations of firewall Firewalls cannot prote...

Limitations of firewall Firewalls cannot protect a network if security rules are not followed properly by an organization or if the rules are not defined properly. Firewalls ar

Functional areas in network management, Question 1 a) Explain how CSMA...

Question 1 a) Explain how CSMA/CD works. b) Describe the term "exponential back-off". c) Describe the differences between "circuit switching" and "packet switching". d) Th

Public key cryptosystem based on rsa technology, Problem: (a) What is ...

Problem: (a) What is the minimum length of a password that could be considered to be "strong" in the context of today's computing power? (b) The security of a PIN system,

What is mac address, MAC Address The address for a machine as it is id...

MAC Address The address for a machine as it is identified at the Media Access Control (MAC) layer in the network structure. MAC address is generally stored in ROM on the n

Marketing, what are the participant of marketing channal?

what are the participant of marketing channal?

Explain belady''s anomaly, Belady's Anomaly Also known FIFO anomaly. G...

Belady's Anomaly Also known FIFO anomaly. Generally, on raising the number of frames given to a process' virtual storage, the program execution is faster, because lesser page

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

Tcp- reliable transport service, TCP-RELIABLE TRANSPORT SERVICE INTRO...

TCP-RELIABLE TRANSPORT SERVICE INTRODUCTION:  TCP is the major transport protocol architecture in the TCP/IP suite. It uses unreliable datagram function offered by IP whe

Explain how the framework will align to the model, MB Enterprise Systems Lt...

MB Enterprise Systems Ltd based in Mauritius is a company specialized in application development with Europe as the main customer base. The company has implemented CMMI and has rec

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