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

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

The security systems development life cycle (secsdlc), The Security Systems...

The Security Systems Development Life Cycle (SecSDLC) The same phases which is used in traditional SDLC can be adapted to support specialized implementation of IS project,At its

Explain how ftp works, QUESTION (a) FTP is a protocol used for the de...

QUESTION (a) FTP is a protocol used for the delivery of files across networks. Explain how FTP works (support your answer with a diagram). (b) How does TCP perform the gi

Basic functions of e-mail system, B a s i c functions of e-mail system ...

B a s i c functions of e-mail system are given as follows: C o mp o sition refers to the procedure of creating messages and the answers. Though any text editor can be

Network management system, Question (a) Draw a typical hybrid star-rin...

Question (a) Draw a typical hybrid star-ring topology paying attention to how the clients and switching hubs are connected. (b) State 3 main differences between a router

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

Internet protocol (ipv6), SUCCESS OF IP:  IP has accommodated dramatic...

SUCCESS OF IP:  IP has accommodated dramatic modification since real design. But basic rules are still appropriate today. There are many new kinds of hardware. SCALING:

Define packet, CONCEPT OF PACKET : Network systems splits data in small ...

CONCEPT OF PACKET : Network systems splits data in small junks or blocks known as packets, which they send individually. Why we required packets rather than bits? The answer to

Routing protocol for a banking network, You have been asked to design a Ban...

You have been asked to design a Banking Network with two primary types of locations.  Branches that will have 3 subnets, one /25 subnet one /26 subnet for ABMS and one /26 s

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