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

Packet sniffers, PACKET SNIFFERS A packet network protocol analyzer is a...

PACKET SNIFFERS A packet network protocol analyzer is a network tool which collects copies of packets from network and analyzes them. It can give network administrator with valu

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

Ping command , In the early days when there were some dozen computers machi...

In the early days when there were some dozen computers machine on the network, it was done individually but now as we have looked that there are millions of computers on the intern

What is meant by certificate revocation, QUESTION (a) Which PKI (Public...

QUESTION (a) Which PKI (Public Key Infrastructure) model is typically favored by business organization? (b) Give one possible use of the "extensions" field of an X.509 certi

Research paper, how much would you charge for minimum 20 pages

how much would you charge for minimum 20 pages

Extended euclidean algorithm, (a) Using the extended Euclidean algorithm, ...

(a) Using the extended Euclidean algorithm, find the multiplicative inverse of 504 mod 67. (b) Decrypt the following ciphertext, which has been encrypted using Caesar cipher:

Attacks on cryptosystems-cryptography, Attacks on Cryptosystems Attacks a...

Attacks on Cryptosystems Attacks are attempts to achieve unauthorized access to secure communications have characteristically used brute force attacks. Attacker may alternatively

Pcm encoder, You have been asked to setup a remote temperature sensing syst...

You have been asked to setup a remote temperature sensing system for an electric furnace. The system consists of a sensor unit which feeds an analogue signal to a PCM encoder. The

Analysis of the problem of cyber attack, Q. Analysis of the Problem of cybe...

Q. Analysis of the Problem of cyber attack? According to the case, The EZ Company is a prominent organization specialized in information integration and visualization technolog

Categories of controls-risk management, Categories of Controls Controlli...

Categories of Controls Controlling risk through mitigation, avoidance or transference is accomplished by implementing controls. There are 4 effective approaches to select the co

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