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

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

Cryptographic hash functions, (a) (i) Bob has public RSA key (n = 77, e...

(a) (i) Bob has public RSA key (n = 77, e = 7). Show that Bob's private key is (d = 43). (ii) Alice wants to send the message m = 13 to Bob. She encrypts the message usi

Ipv6 addressing, IPv6 ADDRESSING IPv6 has 128-bit addresses. A 128-bit...

IPv6 ADDRESSING IPv6 has 128-bit addresses. A 128-bit address adds network prefix and host suffix. An benefit of IPv6 addressing is that there is address classes i.e. prefix/s

Asset identification and valuation-information security, ASSET IDENTIFICATI...

ASSET IDENTIFICATION AND VALUATION This process begins with identification of assets that includes all elements of an organization’s system (people, procedures, data and informa

Fragmentation and path mtu, FRAGMENTATION AND PATH MTU IPv6 source is ...

FRAGMENTATION AND PATH MTU IPv6 source is responsible for fragmentation. Routers simply drop datagrams bigger than network MTU. So source have to fragment datagram to arrive d

Malicious node detection mechanisms, Many applications are vulnerable to in...

Many applications are vulnerable to intrusion attacks and can provide misleading reports about misbehaving nodes. Some of the mechanisms under such a category include the Bayesian

Develop firewall rules based on a fictitious organisation, Question requir...

Question requires you to develop firewall rules based on a fictitious organisation. Scenario: You work for a security-conscious company, xC-Cure, who develop encryption te

Explain web defacement, QUESTION (a) Compare and contrast phishing and ...

QUESTION (a) Compare and contrast phishing and pharming attacks (b) Nowadays, web defacement may not always be visual (i) Explain web defacement (ii) What is the main

What are the main objectives of a risk analysis, QUESTION 1 Risk ana...

QUESTION 1 Risk analysis helps companies prioritize their risks and shows management the amount of money that should be applied to protecting against those risks in a sensib

Why is this setup not secure, Question: a) You are using Active Directo...

Question: a) You are using Active Directory Users under Windows Server 2003 and Computers to configure user objects in your domain, and you are able to change the address and

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