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

What is the benefit of adopting a password aging policy, QUESTION (a) H...

QUESTION (a) Hashing and salting is commonly used as password storage techniques for most applications. Describe how hashing and salting enable secure storage of password (b

Provide a labelled drawing of a standard serial port, Question 1: (a) W...

Question 1: (a) With the help of a diagram show the basic structure of a computer system. (b) Explain as fully as you can each of the parts mentioned above. (c) What are

Ring topology, RING TOPOLOGY In this topology of network the devices a...

RING TOPOLOGY In this topology of network the devices are connected to each other in packed loop. In this network first computer passes data packet to the second and then seco

Network security course work, doing coursework in Network Security to prese...

doing coursework in Network Security to present a possible solution to the problem at hand by creating a prototype of the new network security infrastructure. This new design shou

Address resolution , Mapping between a hardware address and a protocol addr...

Mapping between a hardware address and a protocol address is known Address Resolution. A router or host uses address resolution when it requires to transmit a packet to another dev

Audit or review of the information security issues, Using the selected appr...

Using the selected approach, you should then conduct an audit or review of the information security issues associated with the use of computing facility and report on the findings.

Explain quality management system, Question: Quality management standar...

Question: Quality management standards are seen as a major pillar supporting the drive for continuous quality improvement through TQM. (a) What do you meant by the term ‘Qua

Udp encapsulation, UDP ENCAPSULATION As given in the figure below, UDP...

UDP ENCAPSULATION As given in the figure below, UDP packet is included in IP datagram and the IP datagram is then attached in the Frame.

What is authentication? explain authentication protocols, What is Authentic...

What is Authentication/confirmation?  How it is different from  the Authorization/approval?  Explain in brief different authentication protocols along with their merits and demerit

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