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

Wireless sensor networks, The project will be involving a design and a repo...

The project will be involving a design and a report of which explain the simulation and how it functions. The aim of the project is to help the administrators and staff at the war

Does ssl protect against eavesdropping, QUESTION (a) Consider the follo...

QUESTION (a) Consider the following authentication options A. Using password B. Using pin and fingerprint Which option A or B provides stronger security and why? (b

Asymmetric encryption-cryptography, Asymmetric Encryption Asymmetric encr...

Asymmetric Encryption Asymmetric encryption method makes use of two different but related keys and either key can be used to encrypt or decrypt the message. This method is freque

Access control matrix, You are provided with 3000 sample keystrokes for 5 u...

You are provided with 3000 sample keystrokes for 5 users mentioned above. You can find this data using the ‘Lab 2 User Data' link in the ‘Lab 2' folder on Blackboard. Please note t

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

List vulnerabilities of using wep, Question: The Wired Equivalent Priv...

Question: The Wired Equivalent Privacy (WEP) standard was created in order to give wireless networks safety and security features similar to that of wired networks. (a) L

Perimeter network security system, Title: Perimeter Network Security System...

Title: Perimeter Network Security System Outline Requirements The University is based in Glasgow, and provides higher education services to its students and staff. It is loc

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

Explain how ethernet deals with collisions, (a) Describe how CSMA/CD operat...

(a) Describe how CSMA/CD operates and explain how Ethernet deals with collisions. (b) Describe how the subsequent protocols work: i. ARP ii. DHCP iii. DNS iv. SMTP (c) The

Components of an information system, COMPONENTS OF AN INFORMATION SYSTEM ...

COMPONENTS OF AN INFORMATION SYSTEM The components of an information system are software, data, hardware, people, procedures and Networks. These 6 components are critical to ena

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