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

Address resolution with message exchange, ADDRESS RESOLUTION WITH MESSAGE E...

ADDRESS RESOLUTION WITH MESSAGE EXCHANGE An alternative to local calculation is a distributed function. A computer that requires to find an address transmits a message across

Reason for multiple topologies, REASON FOR MULTIPLE TOPOLOGIES Every t...

REASON FOR MULTIPLE TOPOLOGIES Every topology has disadvantages and advantages, which are described below: IN A RING:  It is simple to coordinate access to other dev

Research paper, how much would you charge for minimum 20 pages

how much would you charge for minimum 20 pages

Compare and contrast between block and stream ciphers, Problem 1 Solve ...

Problem 1 Solve the following Caesar cipher by showing your working: EM KIUM EM AIE EM KWVYCMZML Problem 2 Compare and contrast between block and stream ciphers, listin

Using Technology as Experience Framework, Write a two to three (2-3) page p...

Write a two to three (2-3) page paper in which you: Explain how the Web user interfaces help donors to make decisions. Relate the emotional thread demonstrated in the case study to

How will network datagrams be protected at network layer, (a) Consider the...

(a) Consider the subsequent authentication options: A. Using password. B. Using pin and fingerprint Which option A or B provides stronger security and why? (b) Give

Network management system, Question (a) Draw a typical hybrid star-rin...

Question (a) Draw a typical hybrid star-ring topology paying attention to how the clients and switching hubs are connected. (b) State 3 main differences between a router

Produce a packet from a wireshark capture, Question requires you to produce...

Question requires you to produce a pcap file from a Wireshark capture.  In addition, you must include a screen capture of Wireshark and some specific information regarding the fram

Security goals, what is relation ship between computer security goals?

what is relation ship between computer security goals?

Plain-text using play-fair encryption, What is one-time pad for encryp...

What is one-time pad for encryption?  Describe how it offers both Confusion and Diffusion. Using the letter encoding discussed in class (along with one-time

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