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

Describe what the term session hijacking means, An overall rise in mobility...

An overall rise in mobility, coupled with the falling cost of Wi-Fi equipment, has led to a proliferation of Wi-Fi hot spots in public areas to provide Internet accessibility. Thus

Web accessibility initiative standards, Australian government sites were ma...

Australian government sites were mandated to conform to at least single 'A' level of the World Wide Web Consortium (W3C) Web Accessibility Initiative (WAI) standards, by the end of

Balancing security and access-information security, BALANCING SECURITY AND ...

BALANCING SECURITY AND ACCESS Even with best planning and implementation, it is impossible to obtain perfect security, that is, it is a process, not an absolute. Security should

Data units at different layers of the tcp/ ip protocol suite, Data units at...

Data units at different layers of the TCP/ IP protocol suite The data unit prepared at the application layer is known a message, at the transport layer the data unit build is

Draw the network layout, Question : a) Below is a capture of an Etherne...

Question : a) Below is a capture of an Ethernet II frame which contains an IPv4 packet and a TCP segment. Give the source MAC address for the frame in hexadecimal; the source I

Deployment and implementing of an ids, DEPLOYMENT AND IMPLEMENTING OF AN ID...

DEPLOYMENT AND IMPLEMENTING OF AN IDS The strategy for deploying IDS should consider various factors. These factors will determine the number of administrators required to insta

The Security Systems Development Life Cycle (SecSDLCtle.., #Under what circ...

#Under what circumstances would the use of a SecSDLC be more appropriate than an SDLC?

Half-duplex and full-duplex mode of transmission, Question: a. State br...

Question: a. State briefly three reasons why computer networks are used? b. Differentiate between simplex, half-duplex and full-duplex mode of transmission. c. State any

Determine the round trip time, QUESTION a) Determine the RTT (round tr...

QUESTION a) Determine the RTT (round trip time) between a client requesting a web page of 1024 bytes in size from an internal web server on a 100 Base-T Ethernet. Consider a o

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