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

Programming, SDES encryption and decryption

SDES encryption and decryption

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

Which authorization model could be ideal, Question: (a) Your office ad...

Question: (a) Your office administrator is being trained to take server backups. Which authorization model could be ideal for this situation: MAC, DAC or RBAC? Justify your a

Policy management-information security, POLICY MANAGEMENT Policies should...

POLICY MANAGEMENT Policies should be managed as they constantly change. Good policy development and maintenance make a more resilient organization. All policies undergo tremendou

Md Fayzul karim, How can I get help for Linux automotion configuration (...

How can I get help for Linux automotion configuration (Network, virtualization, security and Firewal etc) with bash scrip. What is the charge for.

Define multimedia and application of multimedia, Describe the salient featu...

Describe the salient features of the multimedia. Also explain the applications of it. Multimedia can be understood as follows: Multimedia is on the whole a media which makes

Negative cycle algorithm in minimum cost flows, QUESTION: (a) Show the...

QUESTION: (a) Show the Negative Cycle Algorithm in Minimum Cost Flows. (b) List the steps added in finding a Negative Cycle. (c) Apply Dijkstra's algorithm on the subs

Limitations of ethical dilemma, The best results obtained in the PIIT class...

The best results obtained in the PIIT classes have been when the technique has been used in tutorial groups, rather than have students submit individual reflections on particular c

CRC, CRC in matlab

CRC in matlab

Address resolution protocol (arp), ADDRESS RESOLUTION PROTOCOL (ARP) T...

ADDRESS RESOLUTION PROTOCOL (ARP) TCP/IP can use any of the three address resolution functions relaying on the addressing procedure used by the underlying hardware. To guarant

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