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

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

Virtual packets, VIRTUAL PACKETS These data packets serve same reason ...

VIRTUAL PACKETS These data packets serve same reason in Internet as frames on LAN. Every packet has a header. Routers, which are normally gateways, transfer packets between ph

Describe types of communication impairments, Question : (a) "Pulse Code...

Question : (a) "Pulse Code Modulation (PCM), as used in telephony, samples a signal at 8 kHz using 256 quantization levels". Outline how this scheme works with the help of ske

What standards are to be applied, Government funding has been given to a un...

Government funding has been given to a university consortium establishing a repository of resources for school teachers. They have engaged you to develop a search facility for teac

Nyquist capacity theorem, (a) Illustrate what you understand by Nyquist Cap...

(a) Illustrate what you understand by Nyquist Capacity Theorem? (b) Consider we wish to transmit at a rate of 64 kbps over a 4 kHz noisy but error-free channel. What is the mini

Semester 2, Do you have assignment solutions for CCE UPES MBA for oil and g...

Do you have assignment solutions for CCE UPES MBA for oil and gas semester 2

RESPONSE, Dropbox’s tool shows how chatbots could be future of cybersecurit...

Dropbox’s tool shows how chatbots could be future of cybersecurity

What is authentication? explain authentication protocols, What is Authentic...

What is Authentication/confirmation?  How it is different from  the Authorization/approval?  Explain in brief different authentication protocols along with their merits and demerit

Ethical hacking penetration testing, Get a copy of Metasploitable at Make...

Get a copy of Metasploitable at Make">http://sourceforge.net/projects/metasploitable/files/Metasploitable2/ Make sure to follow these directions very carefully. You will get po

Explain briefly the role of the physical layer, a) Calculate the CRC for th...

a) Calculate the CRC for the frame below: Frame: 1101011011 Generator: 10011 Message after appending 4 zero bits: 11010110110000 b) OSI refers to a system in which any

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