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 shift operation, SHIFT OPERATION:  This operation replaced all...

SHIFT OPERATION:  This operation replaced all bits to the left one position. For example in the diagram below a 16-bit CRC hardware is given, which needs three Exclusive OR (

Ucsf medical center case study-information security, Example : UCSF Medical...

Example : UCSF Medical Center In the year 2002, the University of California, San Francisco (UCSF) Medical Center received an email message from someone who claimed to be a doct

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

Incident response, Incident Response: Complete the following sections as id...

Incident Response: Complete the following sections as identified from your Incident Response template (in MS Word format): Update the table of contents (autogenerated) Separate

Elliptic Curves, #questioAn elliptic curve y^2=x^3+ax+b(mod29) includes poi...

#questioAn elliptic curve y^2=x^3+ax+b(mod29) includes points P=(7, 15) and Q=(16, 13) a)Determine the equation of the crve b) Determine all values of x for which there is no point

Arrangement of self-learning switches, QUESTION a) Consider the speed ...

QUESTION a) Consider the speed of propagation of an electrical signal is same to 2x10 8 m/s, evaluate the ratio of the propagation delay to the transmit time for the given typ

Syntax conversion, Write down the significance of the syntax conversion . S...

Write down the significance of the syntax conversion . Syntax Conversion is described below: Syntax conversion is a significant function carried out in the presentation layer. I

Describe benefits of effective communication, Question: (a) Explain the...

Question: (a) Explain the following terms: Information Communication Technology, Operating System and Application Software. (b) Define what a computer is, give four anatomi

Topology, What is the concept of topology?

What is the concept of topology?

Example bus network , Ethernet is a commonly used LAN technology. It was di...

Ethernet is a commonly used LAN technology. It was discovered at EXROX PARC(Palo Alto Research Center) in 1970s.Xerox, Intel and Digital described it in a standard so it is also kn

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