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

Attacks on cryptosystems-cryptography, Attacks on Cryptosystems Attacks a...

Attacks on Cryptosystems Attacks are attempts to achieve unauthorized access to secure communications have characteristically used brute force attacks. Attacker may alternatively

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

Risk management discussion points, Risk Management Discussion Points Org...

Risk Management Discussion Points Organizations should define level of risk it can live with Risk appetite: it defines quantity and nature of risk which organizations are wil

Explain the dimension of service quality, Problem 1: Discuss how TWO of...

Problem 1: Discuss how TWO of the following gurus have contributed to the Quality Movement, highlighting the major points of their philosophies: (a) Edward Deming (b) Jose

AES, define .

define .

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

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

Access control devices-cryptography, ACCESS CONTROL DEVICES Successful a...

ACCESS CONTROL DEVICES Successful access control system includes number of components, which depends on system’s requirements for authentication and authorization. Powerful auth

Frame format and error detection, FRAME FORMAT AND ERROR DETECTION The...

FRAME FORMAT AND ERROR DETECTION The changed frame format also adds CRC. If there is an error happened in frame, then it typically causes receiver to removed frame. The frame

Systems development life cycle (sdlc)-information security, SDLC Systems ...

SDLC Systems development life cycle (SDLC) is process of developing information systems through analysis, design, investigation, implementation and maintenance. SDLC is called as

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