User Account

All Pages

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

Limitations of ethical dilemma, The best results obtained in the PIIT class...

The best results obtained in the PIIT classes have been when the technique has been used in tutorial groups, rather than have students submit individual reflections on particular c

What are the intermediate systems and how they work, Question: a) Expla...

Question: a) Explain what the following intermediate systems are and how they work? i. Repeater ii. Bridge b) A service is formally specified by a set of primitives (op

Packet filtering firewall, Packet Filtering Firewall Packet filtering i...

Packet Filtering Firewall Packet filtering is a network security mechanism that works by controlling what data can flow in and out of the network. The basic device that interco

Explain symmetric and asymmetric encryption system, Question 1: (a) Dif...

Question 1: (a) Differentiate between symmetric and asymmetric encryption system. (b) Describe how a digital signature is created. (c) Explain briefly what SSL (secure so

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

Information security policy practices and standards, INFORMATION SECURITY P...

INFORMATION SECURITY POLICY PRACTICES AND STANDARDS Management from all the communities of interest should consider policies as basis for all information security efforts. Polic

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

Frame format and error detection, FRAME FORMAT AND ERROR DETECTION The...

FRAME FORMAT AND ERROR DETECTION The changed frame format also adds CRC. If there is an error happened in frame, then it typically causes receiver to removed frame. The frame

Explain the operation of the matchmaker middle agent, Question 1: (a) E...

Question 1: (a) Explain the operation of the "matchmaker" middle agent. (b) Describe why broker middle agents are more efficient in terms of the time taken for a service to

Listing assets in order of importance-risk management, Listing Assets in Or...

Listing Assets in Order of Importance Weighting should be created for each category based on the answers to questions. The relative importance of each asset is calculated usin

Write Your Message!

Captcha
Order Assignment

Featured Services

Order Now

Popular Subjects

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!

Submit Assignment

Academics

Major Subjects

Majors

Get In Touch

whatsapp: +91-977-207-8620

Phone: +91-977-207-8620

Email: [email protected]

TERMS & POLICIES

HELP & SUPPORT

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd