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

What is the size of the initialization vector n wpa, Question : Wi-Fi p...

Question : Wi-Fi protected access (WPA) was specified by the Wi-Fi alliance with the primary aim of enhancing the security of existing 802.11 networks. However, WPA was only a

Securing the network using a packet filter firewall, 1. Network Design ...

1. Network Design Design your network giving appropriate IP addresses for your hosts. Provide a topology and table showing your addressing scheme. 2. F i re wall po

Explain the approaches to lric modeling, (a) Cost allocation mechanisms ar...

(a) Cost allocation mechanisms are important when it comes to establishing other aspects of inter-firm compensations and how these are transferred to the users. There are two pri

Firewalls-information security, Firewalls A firewall in an information s...

Firewalls A firewall in an information security program that prevents specific types of information from moving between the outside world and the inside world. The firewall may

Describe the procedure known as byte stuffing, Question: (a) For the b...

Question: (a) For the bit stream 010011, sketch the waveforms for each of the code indicated. Assume the following: the signal level for the previous bit for NRZI was a 1

Ipv6 next header, IPV6 NEXT HEADER It is given in the figure below:

IPV6 NEXT HEADER It is given in the figure below:

What is the role of an intrusion detection system, Problem: (a) What i...

Problem: (a) What is a firewall and which are its most important tasks? (b) What is the difference between default deny and default permit? Which advantages and disadvanta

[email protected], Re: Website Google Ranking Hello! Hope yo...

Re: Website Google Ranking Hello! Hope you are doing well. I discovered some major issues in your website which might be the cause for the Google Penalties and poor search ranki

Summarises the firewall protocols, Your rules should ensure that Internet a...

Your rules should ensure that Internet access will be restricted to the following: Only the following services will be permitted as OUTBOUND traffic (to the Internet from the DM

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