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

Ids-information security, IDS Intrusion is a attack on information assets...

IDS Intrusion is a attack on information assets in which instigator attempts to gain entry into or disrupt normal system with harmful intent Incident response is an identificatio

Using icmp reachability, USING ICMP TO TEST REACHABILITY:  ICMP can a...

USING ICMP TO TEST REACHABILITY:  ICMP can also be used to test several tools. An Internet host A, is reachable from another host B, if data packets can be send from A to B. P

Mobile wireless networks , Is standard TCP effective in mobile wireless net...

Is standard TCP effective in mobile wireless networks that operate with the IEEE 802.11 wireless local area network protocol?Discuss the issue

Describe des encryption, (a) Describe DES encryption with a block diagram a...

(a) Describe DES encryption with a block diagram and brief steps. (b) How does triple DES improve security. What is the effective key length of triple DES? How can 3DES be compa

Differences between a hacker and a cracker, Question: (a) Which of the...

Question: (a) Which of the following is not a goal of security: i) detection ii) prevention iii) recovery iv) prosecution (b) You are an honest student. One day you

Types of idss and detection methods, Types of IDSs and Detection Methods ...

Types of IDSs and Detection Methods IDSs operate as network based, host based, or application based systems and focused on protecting network information assets. All the IDSs us

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

Rsa block and vernam stream ciphers, RSA Block and Vernam Stream Ciphers ...

RSA Block and Vernam Stream Ciphers This assignment involves writing two small Python scripts and a report. Before you start you must download the ?le summarysheets.zip from th

Explain the schemes for distribution of public keys, (a) What is a pseudora...

(a) What is a pseudorandom generator? Give an example describing how it works. (b) Explain the key components of a wireless network and their purpose. (c) Describe the authen

Lan topologies, Network can be distinguished by shape. According to which t...

Network can be distinguished by shape. According to which there are three most popular methodologies, which are shown as follows; Star Ring Bus

Write Your Message!

Captcha
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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd