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

WEP-BASED AUTHENTICATION, Why is WEP-based authentication pointless?

Why is WEP-based authentication pointless?

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

how much would you charge for minimum 20 pages

Draw the waveform for an asynchronous transmission, Question: (a) Draw...

Question: (a) Draw the waveform for an asynchronous transmission with the following specifications: Character "H", one even parity bit, one start bit, one stop bit, and a b

Base lining-risk management, Base lining •    Organizations do not have ...

Base lining •    Organizations do not have any contact to each other •    No two organizations are identical to each other •    The best practices are a moving target •    K

Discuss a communication channel, Question An organization is planning t...

Question An organization is planning to connect its networks to the Internet. The network is located within a four story building. A web server supporting online sales is also

Discuss five alternative testing techniques, QUESTION Testing of a Busi...

QUESTION Testing of a Business Continuity Plan (BCP) does not need to be costly or to interrupt the daily operations of the business. The result of the test should also be look

Ip datagram format, IP DATAGRAM SIZE:  Datagrams may have different si...

IP DATAGRAM SIZE:  Datagrams may have different sizes i.e. Header area is generally fixed (20 octets) but can have various options. Data area may contain between 1 octet and 6

Benchmarking-information security, Benchmarking An alternative approach to...

Benchmarking An alternative approach to risk management is Benchmarking. It is process of seeking out and studying practices in other organizations which one’s own organization de

Describe how lower bounds on arc flows, QUESTION: (a) Suppose the graph ...

QUESTION: (a) Suppose the graph below, use the Flow Decomposition method to list the cycles and paths produced. (b) Describe how Lower Bounds on Arc Flows are eliminated

Vulnerability scanners, VULNERABILITY SCANNERS Active vulnerability scan...

VULNERABILITY SCANNERS Active vulnerability scanners scan networks for detailed information, it initiate traffic to determine security holes. This scanner identifies usernames a

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