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

Ip Datagram, Size of Option field of an ip datagram is 20 bytes. What is th...

Size of Option field of an ip datagram is 20 bytes. What is the value of HLEN? What is the value in binary?

Quote, How much would it cost to have a project completed by tomorrow night...

How much would it cost to have a project completed by tomorrow night?

Introduction to planning for security, INTRODUCTION TO PLANNING FOR SECURIT...

INTRODUCTION TO PLANNING FOR SECURITY The creation of an information security program begins with creation and review of organization’s information security policies, standards,

Introduction to security and personnel, INTRODUCTION TO SECURITY AND PERSON...

INTRODUCTION TO SECURITY AND PERSONNEL When implementing information security, there are several human resource issues that should be addressed. They are •    Positioning and n

Briefly list functions of a public key infrastructure, Question: (a) Wh...

Question: (a) What is the major problem with public key encryption when compared to symmetric key encryption? (b) Consider the following protocol for communication between t

Virtual packets, VIRTUAL PACKETS These data packets serve same reason ...

VIRTUAL PACKETS These data packets serve same reason in Internet as frames on LAN. Every packet has a header. Routers, which are normally gateways, transfer packets between ph

Describe types of communication impairments, Question : (a) "Pulse Code...

Question : (a) "Pulse Code Modulation (PCM), as used in telephony, samples a signal at 8 kHz using 256 quantization levels". Outline how this scheme works with the help of ske

Half-duplex and full-duplex mode of transmission, Question: a. State br...

Question: a. State briefly three reasons why computer networks are used? b. Differentiate between simplex, half-duplex and full-duplex mode of transmission. c. State any

What is b-router, B-Router Hybrid devices that has the features of bot...

B-Router Hybrid devices that has the features of both routers and bridges . A bridge router or brouter is a network machine that acts as a router and as a bridge. The brout

Differentiate between private key and public key encryption, Problem (...

Problem (a) Differentiate between private key and public key encryption. (b) What issue with private key encryption is resolved with public key encryption? (c) Describe

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