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

Define bridges, Bridges perform both in the data link layers and physical...

Bridges perform both in the data link layers and physical of LANs of same kind. They split a bigger network in to smaller segments. They have logic that accept them to store the

CS, Discuss how developers should apply the following countermeasures to im...

Discuss how developers should apply the following countermeasures to improve the security of their code:

Technology, how can you enter the ASVAB practice test on line?

how can you enter the ASVAB practice test on line?

Tcp and udp, TCP and UDP End-to-end delivery application is connection...

TCP and UDP End-to-end delivery application is connection less. The basic function of connectionless service are as given: It adds extension of LAN abstraction. It has simp

Components of an information system, COMPONENTS OF AN INFORMATION SYSTEM ...

COMPONENTS OF AN INFORMATION SYSTEM The components of an information system are software, data, hardware, people, procedures and Networks. These 6 components are critical to ena

Md Fayzul karim, How can I get help for Linux automotion configuration (...

How can I get help for Linux automotion configuration (Network, virtualization, security and Firewal etc) with bash scrip. What is the charge for.

ISDN, Explain the architecture of ISDN.....?

Explain the architecture of ISDN.....?

Design a network layout, QUESTION: (a) Below is a capture of an Ethern...

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 sourc

Describe how lower bounds on arc flows, QUESTION: (a) Suppose the graph ...

QUESTION: (a) Suppose the graph below, use the Flow Decomposition method to list the cycles and paths produced. (b) Describe how Lower Bounds on Arc Flows are eliminated

Computer security, Assume that the RSA problem is hard, prove that the RSA ...

Assume that the RSA problem is hard, prove that the RSA encryption is secure against IND- CPA. Provide a game between an adversary A and a simulator (or challenger) B.

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