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

Describe benefits of effective communication, Question: (a) Explain the...

Question: (a) Explain the following terms: Information Communication Technology, Operating System and Application Software. (b) Define what a computer is, give four anatomi

Internet protocol(ip), Internet Protocol IP Gives computer-to-comp...

Internet Protocol IP Gives computer-to-computer communication. Host and receiver addresses are computers. This is also known machine-to-machine communication.

ISDN, Explain the architecture of ISDN.....?

Explain the architecture of ISDN.....?

Network security course work, doing coursework in Network Security to prese...

doing coursework in Network Security to present a possible solution to the problem at hand by creating a prototype of the new network security infrastructure. This new design shou

Inverse z transform, table for inverse z transform

table for inverse z transform

Derive the transmitted crc header checksum, QUESTION (a) Consider the f...

QUESTION (a) Consider the following digital bit stream 01001100 is to be encoded in: i. NRZ-I ii. Pseudoternary iii. Manchester iv. Differential Manchester Show th

encrypt and decryption using rsa with the prime numbers, Problem (1) -...

Problem (1) - Alice, Bob and Charlie have a secret key a=3, b=4, c=5, respectively. - They want to find a common secret key using Diffie-Hellan key exchange protocol (with g

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

Difference between flow control and congestion control, (a) Describe briefl...

(a) Describe briefly the difference between flow control and congestion control in relation to a connection-oriented protocol such as TCP. (b)  What is the initial rate of data

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

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