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

Basic types of agent in order of increasing generality, Question 1: (a)...

Question 1: (a) Define Artificial Intelligence. (b) Briefly describe the categories for the definition of Artificial Intelligence. (c) Identify the four basic types of

Secure a wireless network, Secure a Wireless Network WIRELES Most onli...

Secure a Wireless Network WIRELES Most online retailers provide some type of privacy statement. Many statements are long, and appear in small print, and many appear to be simi

Syntax conversion, Write down the significance of the syntax conversion . S...

Write down the significance of the syntax conversion . Syntax Conversion is described below: Syntax conversion is a significant function carried out in the presentation layer. I

Application layer protocol, Problem a) Give the destination IP address, up...

Problem a) Give the destination IP address, upper layer protocol, TTL in decimal and header checksum in hexadecimal; the source port number and the destination port number in deci

What do you understand by the concept web of trust, Question: a) Name ...

Question: a) Name a method to allow a person to send a confidential email to another person, without risks of a third-party reading the email. Describe briefly the operations

Explain the random key distribution, Q. Explain the random key distribution...

Q. Explain the random key distribution? The triple key management mechanisms ensure a better and complete security solution using the random key distribution mechanism. In this

Computer security, Implementing an effective online authentication scheme i...

Implementing an effective online authentication scheme in practice faces many challenges. Systems with highly sensitive data often require multifactor authentication. But, requirin

What do you meant by network address translation, Problem: (a) What do ...

Problem: (a) What do you meant by Network Address Translation (NAT)? Why is it used? (b) Given the following information by your ISP about your newly acquired Frame Relay c

Need for security-information security, NEED FOR SECURITY Primary missio...

NEED FOR SECURITY Primary mission of information security to ensure that the systems and contents stay the same If no threats, could focus on improving the systems, resulting in

What is information security, What is information security Information s...

What is information security Information security protects information (and facilities and systems which store, use and transmit it) from a broad range of threats, in order to p

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