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

Risk assessment, RISK ASSESSMENT Risk assessment is a step in a risk man...

RISK ASSESSMENT Risk assessment is a step in a risk management technique. Risk assessment is the determination of quantitative or qualitative value of risk related to a concrete

Problem of spam mail, Topic -Spam is an ever-growing problem, with some net...

Topic -Spam is an ever-growing problem, with some network administrators reporting that 90% or moreof the email delivered to their mail servers is spam. Identify and briefly evalua

Location to e-mail messages are saved, In the e-mail system, where the e-ma...

In the e-mail system, where the e-mail messages are saved and why? E-mail messages are saved in user’s private electronic mailbox. A mailbox refers to a local/domestic hard drive c

Issue-specific security policy (issp), Issue-Specific Security Policy (ISSP...

Issue-Specific Security Policy (ISSP) The ISSP addresses specific areas of technology, needs frequent updates and having statement on organization’s position on a particular iss

Determine the functions of security components, You are designing a Demilit...

You are designing a Demilitarized zone for a large corporation. Using design best practice, and the information that you have learned so far, propose a design that will provide the

Packets and frames, PACKETS: Packet is a generic word that define to sma...

PACKETS: Packet is a generic word that define to small code of data. Packet have different format. Each hardware needs different packet format.  FRAME: A hardware frame or

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

how much would you charge for minimum 20 pages

Firewall architectures-screened subnet architecture, Screened Subnet Archit...

Screened Subnet Architecture This setup provides an extra security layer to screened host architecture by creating a perimeter subnet which further isolates internal network f

Improving domain blacklisting - spam mail, Improving domain blacklisting: ...

Improving domain blacklisting: Current domain blacklisting techniques are not very effective as spammers keep replacing blacklisted domains with newly registered domains. Also

Calculate the total latency, Question (a) Inspect the following ifconfi...

Question (a) Inspect the following ifconfig output of an IPv6 interface: i. What is the hidden Hardware Address of the interface on Line #1? ii. What is the hidden subn

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