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

Differences between a hacker and a cracker, Question: (a) Which of the...

Question: (a) Which of the following is not a goal of security: i) detection ii) prevention iii) recovery iv) prosecution (b) You are an honest student. One day you

Digital signatures, Digital Signatures Digital Signatures are encrypted ...

Digital Signatures Digital Signatures are encrypted messages which can be proven mathematically to be authentic. These are created in response to rising requirement to verify in

Define half-duplex, A  half-duplex (HDX) system gives communication in b...

A  half-duplex (HDX) system gives communication in both directions, but only one direction at a time. Hardly, once a party stats receiving a signal, it must need for the transmi

Compare the suitability and properties of isdn and adsl, Question : An a...

Question : An aircraft manufacturing company is considering linking the network of one of its offices to the network of its Headquarter using either xDSL or ISDN. i. Compare

Determine the round trip time, a) determine the RTT (round trip time) betwe...

a) determine the RTT (round trip time) between a client requesting a web page of 1024 bytes in size from an internal web server on a 100 Base-T Ethernet. Assume a one-way propagati

Describe the two possible configurations for 3des, QUESTION (a) Describ...

QUESTION (a) Describe the two possible configurations for 3DES (b) What is the main disadvantage of 3DES? (c) Why are most modern symmetric algorithm block ciphers? (d

Websphere administrator, Websphere Administrator: Working as Webspher...

Websphere Administrator: Working as Websphere Administrator in the department called DART (Database Architecture Re-Engineering and Tuning). The major responsibilities are t

Explain briefly how go-back-n operates, Question: a) There are two basi...

Question: a) There are two basic approaches to dealing with errors in the presence of pipelining. One way is Go-Back-N and the other strategy is Selective Repeat. i. Explain

Ip datagrams, on LAN,where are IP datagrams transported?

on LAN,where are IP datagrams transported?

SNORT, Detect each visit to www.google.com that is made by the machine. o S...

Detect each visit to www.google.com that is made by the machine. o Send an alert when an activity relating to network chat is detected. o Send an alert when an attempt is made for

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