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

Need assignemnt help in information security assignemnt, Need Assignemnt he...

Need Assignemnt help in Information security assignemnt

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.

What is the main security vulnerability of ipv4, Question: (a) What is...

Question: (a) What is the main security vulnerability of IPv4? (b) Which protocol can be used for secure remote login? (c) Distinguish between the transport and tunnel

X.509, Consider the details of the X.509 certificate shown below. a. Identi...

Consider the details of the X.509 certificate shown below. a. Identify the key elements in this certificate, including the owner''s name and public key, its validity dates, the nam

Looking for data network security assignment, I am ryan, i am looking for d...

I am ryan, i am looking for data security and network assignment help, Do you have experts in data security?

Security policies, implementing password policy in organisation

implementing password policy in organisation

What is triple key management scheme, Q. What is Triple Key Management Sche...

Q. What is Triple Key Management Scheme? The triple key management mechanism provides optimum security by enabling the use of two pre-deployed keys for each of the WS nodes, an

How to create a security policy, Five years ago, Calgary Kids' Cloth Ltd wa...

Five years ago, Calgary Kids' Cloth Ltd was just a small retail store in downtown Calgary. The company started their own factory in SE Calgary to produce outdoor clothes for kids.

Asset identification and valuation-information security, ASSET IDENTIFICATI...

ASSET IDENTIFICATION AND VALUATION This process begins with identification of assets that includes all elements of an organization’s system (people, procedures, data and informa

State the fermat-euler theorem, Question: (a) Prove that every positive...

Question: (a) Prove that every positive integer n can be factorized into a product of prime powers. (b) State the Fermat-Euler theorem as needed in the RSA system. (c) Us

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