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

What is network address translation, Question: (a) What is Network Add...

Question: (a) What is Network Address Translation (NAT)? Why is it used? (b) Given a following information by your ISP about your newly acquired Frame Relay connection:

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

how much would you charge for minimum 20 pages

What is border gateway protocol, Border Gateway Protocol It is a proto...

Border Gateway Protocol It is a protocol needed to advertise the set of networks that can be achieved within an autonomous machine. BGP activates this information to be shared

Emerging threats related to use of networks, Question requires you to submi...

Question requires you to submit a proposal based on the research report topic you will be addressing in the second assignment.  Note:  before commencing research on the topic, y

What is ftam-file transfer access and management, Describe what the FTAM se...

Describe what the FTAM services are. FTAM  stand for the File Transfer Access and Management: FTAM is an ISO application protocol which performs the operations on files such as.

Information asset classification-risk management, Information asset classif...

Information asset classification-risk management A number of organizations have data classification schemes (for instance confidential, internal, public data). The classificat

What do you understand by the term integrity, Question: (a) What do yo...

Question: (a) What do you understand by the term "integrity"? (b) Which type of attack denies authorized users access to network resources? (c) You have discovered tha

Wireless local area network, a) Wireless local area network (WLAN) technol...

a) Wireless local area network (WLAN) technologies constitute a fast-growing market introducing the flexibility of wireless access into office, home, or production environments. G

Algorithm, algorithm on simple intrest

algorithm on simple intrest

Plaintext, how to encryt the data in plaintext cipher

how to encryt the data in plaintext cipher

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