Placeholders for the plaintext characters, 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:- Placeholders for the plaintext characters

Gateways, Gateways They transfer packets among network machines that h...

Gateways They transfer packets among network machines that have different protocols (e.g. between a WAN and a LAN). They access a packet formatted for one protocol and change

Rsa block and vernam stream ciphers, RSA Block and Vernam Stream Ciphers ...

RSA Block and Vernam Stream Ciphers This assignment involves writing two small Python scripts and a report. Before you start you must download the ?le summarysheets.zip from th

Define network, A Network is described as a system for connecting compu...

A Network is described as a system for connecting computers using a single transmission technology. The computers can interact with each other in a network. They can receive an

Digital certificates-cryptography, Digital Certificates Digital Certific...

Digital Certificates Digital Certificates are electronic document having key value and identifying information about entity which controls key. Digital signature which is attach

Technology, how can you enter the ASVAB practice test on line?

how can you enter the ASVAB practice test on line?

Efforts of advanced research project agency, ADVANCED RESEARCH PROJECT AGEN...

ADVANCED RESEARCH PROJECT AGENCY (ARPA) The efforts of ARPA was to active all its research groups have accept to new era computers. For this purpose ARPA started investing in wa

Sequential label and supply, What questions should Iris ask Charlie about t...

What questions should Iris ask Charlie about the new job, about Kelvin''s team, and about the future of the company?

Placeholders for the plaintext characters, Encode the following plaintext, ...

Encode the following plaintext, using the Caesar cipher:             LORD OF THE RINGS b) The following ciphertext              jw njbh lxmn cx kanjt has been encoded usi

Point to point transmission(ppp), Normal 0 false false fals...

Normal 0 false false false EN-US X-NONE X-NONE

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