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

Asymmetric encryption-cryptography, Asymmetric Encryption Asymmetric encr...

Asymmetric Encryption Asymmetric encryption method makes use of two different but related keys and either key can be used to encrypt or decrypt the message. This method is freque

Find the capacity of the wcdma, Question: (a) Describe the term interfe...

Question: (a) Describe the term interference in the space, time, frequency, and code domain. (b) Consider a 1 G - AMPS: 824-849 MHz (forward) ; 869-894 MHz (reverse). B

Access control devices-cryptography, ACCESS CONTROL DEVICES Successful a...

ACCESS CONTROL DEVICES Successful access control system includes number of components, which depends on system’s requirements for authentication and authorization. Powerful auth

Explain the dimension of service quality, Problem 1: Discuss how TWO of...

Problem 1: Discuss how TWO of the following gurus have contributed to the Quality Movement, highlighting the major points of their philosophies: (a) Edward Deming (b) Jose

Explain transposition ciphers and substitution cipher, What do you understa...

What do you understand by cryptanalysis? Discuss about the transposition ciphers substitution cipher, and onetime pads. The messages which are intended to transmit secretly and

#title.TIPS., 1. For this project, assume that an organization has five ser...

1. For this project, assume that an organization has five servers. Server 1 has a TCO of $25,000, Servers 2 and 3 have a TCO of $37,000 each, and the remaining two servers— Servers

Network security keys, The three primary types of network protection are th...

The three primary types of network protection are the same as the three primary areas where a network can be attacked. Every network needs protection against people-related, hardwa

Carrier sense multiple access (csma), CARRIER  SENSE MULTIPLE ACCESS (CSMA...

CARRIER  SENSE MULTIPLE ACCESS (CSMA) There is no central access management when computers transfer on Ethernet. For this solution the Ethernet employs CSMA to coordinate tran

Explain the terms used in network security, Question 1 (a) Explain b...

Question 1 (a) Explain briefly the following terms as used in network security: (i) Denial of service (DoS) attack (ii) Birthday attack (iii) DeMilitarized Zone

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