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

Direct indexing, DIRECT INDEXING It is less usually known method. It i...

DIRECT INDEXING It is less usually known method. It is possible only is cases where protocols address are given from a compact range. In the diagram below an example of direct

Computer fundamental & M S OFFICCE, Convert (111011)2 to ( )10

Convert (111011)2 to ( )10

Cyber troll case, According to the case, The EZ Company introduced a new te...

According to the case, The EZ Company introduced a new technology, focusing on the principles of informationintegration and visualization. The company started negotiatinga saleto a

Briefly list functions of a public key infrastructure, Question: (a) Wh...

Question: (a) What is the major problem with public key encryption when compared to symmetric key encryption? (b) Consider the following protocol for communication between t

Short term scheduler, Short term Scheduler function , also shown as a disp...

Short term Scheduler function , also shown as a dispatcher runs most frequently, and creates the finest-grained decision of which program could run next. This scheduler is called

Functional areas in network management, Question 1 a) Explain how CSMA...

Question 1 a) Explain how CSMA/CD works. b) Describe the term "exponential back-off". c) Describe the differences between "circuit switching" and "packet switching". d) Th

Analysis phase in the building-block approach, QUESTION: a) Explain fou...

QUESTION: a) Explain four issues that are generally addressed in the Needs Analysis phase in the building-block approach to network design. b) Sketch a typical hybrid star-b

Identify possible controls-information security, Identify Possible Controls...

Identify Possible Controls For each threat and linked vulnerabilities which have residual risk, create primary list of control ideas. Residual risk is the risk which remains to

Programming, SDES encryption and decryption

SDES encryption and decryption

What is b-router, B-Router Hybrid devices that has the features of bot...

B-Router Hybrid devices that has the features of both routers and bridges . A bridge router or brouter is a network machine that acts as a router and as a bridge. The brout

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