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

Draw the full network diagram, Problem (a) Below is a capture of an E...

Problem (a) Below is a capture of an Ethernet II frame which contains an IPv4 packet and a TCP segment. The second screen capture is from the data portion of the frame.

Wireless networks, Wireless Networks The origin of wireless networks a...

Wireless Networks The origin of wireless networks and their ubiquity in the technological environment poses a new type of exposure and vulnerability for network security. Cont

Direct sequence modulation, Question 1 a) Provide three advantages of ...

Question 1 a) Provide three advantages of using optical fiber. b) Distinguish between "Direct Sequence Modulation" and "Frequency Hopping" c) Decribe the purpose of using "

Packet filtering firewall-dynamic packet filtering, Dynamic Packet Filterin...

Dynamic Packet Filtering Dynamic Packet Filtering is also referred to as stateful firewalling. Here the firewall maintains the status of connections as well. When a connection

Ring topology, RING topology all computers are connected in loop. A ring ...

RING topology all computers are connected in loop. A ring topology is a network topology in which every node connects to exactly two other devices, forming a single continuous pa

Describe how lower bounds on arc flows, QUESTION: (a) Suppose the graph ...

QUESTION: (a) Suppose the graph below, use the Flow Decomposition method to list the cycles and paths produced. (b) Describe how Lower Bounds on Arc Flows are eliminated

CS, Discuss how developers should apply the following countermeasures to im...

Discuss how developers should apply the following countermeasures to improve the security of their code:

Packet filtering firewall-stateless packet filtering, Stateless Packet Filt...

Stateless Packet Filtering Stateless or static packet filtering is the most straightforward kind of packet filtering that allows or disallows data transfer based on the addres

The major decision hierarchy for disclosing security problem, QUESTION ...

QUESTION The major decision hierarchy for disclosing security problems is if the problem is with the product owned by the business or if it is used by the business. Although th

Explain the rsa algorithm, Question: (a) What is the minimum length of...

Question: (a) What is the minimum length of a password that could be considered to be "strong" in the context of today's computing power? (b) The security of a PIN system,

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