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

What is internet, The Internet is known as the set of networks connect...

The Internet is known as the set of networks connected by routers that are configured to pass traffic among any machine attached to any network in the set. By internet several

Minimum cost flow problem, QUESTION (a) A convex flow problem is a no...

QUESTION (a) A convex flow problem is a non linear network flow problem. Explain how a convex flow problem could be transformed into a Minimum Cost Flow problem. (b) Exp

Describe how ethernet deals with collisions, Problem (a) The IEEE 802 seri...

Problem (a) The IEEE 802 series of standards describe both the Physical and Data Link layers of their respective technologies. Two important standards are 802.3 and 802.5, respect

Describe header fields present in a udp segment, Question (a) In relati...

Question (a) In relation to a TCP segment structure, provide the fields responsible for: i. Connection Management ii. Flow Control iii. Error Control iv. Reliable, in-order

The cost benefit analysis (cba) formula, The Cost Benefit Analysis (CBA) Fo...

The Cost Benefit Analysis (CBA) Formula CBA determines that whether the control alternative being evaluated is worth cost incurred to control vulnerability or not. CBA easily ca

Nessus vulnerability, You see two IP addresses. The IP address 192.168.58.1...

You see two IP addresses. The IP address 192.168.58.130 is the one of Bt4. The IP address 192.168.58.133 has ports 135 and 445 open; which indicates that it is a Windows machine. S

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

Issue specific security policy, Why an organization need the issue specific...

Why an organization need the issue specific security policy

Explain how ftp works, QUESTION (a) FTP is a protocol used for the de...

QUESTION (a) FTP is a protocol used for the delivery of files across networks. Explain how FTP works (support your answer with a diagram). (b) How does TCP perform the gi

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