User Account

All Pages

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

Categories of controls-information security, Categories of Controls Cont...

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

Explain authentication process in a synchronous token system, Question: ...

Question: (a) Explain briefly the PCI Control Objectives which enterprises must meet to be compliant with the Payment Card Industry Data Security Standard (PCI DSS). Specify a

What is data spoliation, QUESTION (a) What do you meant by data spoli...

QUESTION (a) What do you meant by data spoliation? (b) Justify the following statement: "Disk imaging differs from creating a standard backup of disk." (c) Why do yo

Difference between flow control and congestion control, (a) Describe briefl...

(a) Describe briefly the difference between flow control and congestion control in relation to a connection-oriented protocol such as TCP. (b)  What is the initial rate of data

Intrusion detection and classification, i want to detec and classify networ...

i want to detec and classify network anomaly detection based on KDD99 data set using swarm intelligence

Selecting a risk control strategy, Selecting a Risk Control Strategy Risk...

Selecting a Risk Control Strategy Risk controls involve selecting one of the 4 risk control strategies for every vulnerability. The flowchart is shown in the figure given below

What are the main objectives of a risk analysis, QUESTION 1 Risk ana...

QUESTION 1 Risk analysis helps companies prioritize their risks and shows management the amount of money that should be applied to protecting against those risks in a sensib

Introduction, Transposition technique

Transposition technique

Http request message, Question (a) Consider that you enter the subsequent ...

Question (a) Consider that you enter the subsequent URL in the address bar of a popular web client and that both the server and client accepts HTTP version 1.1. i. What can be

Write Your Message!

Captcha
Order Assignment

Featured Services

Order Now

Popular Subjects

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!

Submit Assignment

Academics

Major Subjects

Majors

Get In Touch

whatsapp: +91-977-207-8620

Phone: +91-977-207-8620

Email: [email protected]

TERMS & POLICIES

HELP & SUPPORT

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