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

Difference between synchronous tdm and statistical tdm, Question (a) A CRC...

Question (a) A CRC is constructed to generate a 4-bit FCS for an 11-bit message. The divisor polynomial is X 4 + X 3 + 1 (i) Encode the data bit sequence 00111011001 using po

Csma/ca, CSMA/CA Wireless needs collision avoid ness rather than colli...

CSMA/CA Wireless needs collision avoid ness rather than collision checking. Transmitting computer puts very short codes to receiver. Receiver responds with short message getti

Securing the components-information security, SECURING THE COMPONENTS Co...

SECURING THE COMPONENTS Computer can be subject of an attack or the object of an attack. When subject of an attack, computer is used as lively tool to conduct attack. The figure

Ip datagram, IP DATAGRAM Various options can be included to IP header,...

IP DATAGRAM Various options can be included to IP header, e.g., source route, record route and timestamp. Header with no function has H. LEN field value 5; data starts immedia

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

Mention most relevant clause of iso 27001:2005, QUESTION (In this ques...

QUESTION (In this question, you will need to use the ISO 27001:2005 and ISO 27002:2005 standards) For each of the situations below, comment on the following: 1. Mention

Protocols for secure communications-cryptography, Protocols for Secure Comm...

Protocols for Secure Communications Securing Internet Communication by using S-HTTP and SSL Secure Socket Layer (SSL) protocol is a protocol that uses public key encryption t

Mr David, why is it that sometime we put password in our account to login o...

why is it that sometime we put password in our account to login or signup and it would not work?

English language, how can i talk English fast

how can i talk English fast

Describe phishing attacks, QUESTION (a) (i) Describe Phishing attacks. ...

QUESTION (a) (i) Describe Phishing attacks. (ii) Distinguish between Phishing and Spear Phishing attacks. (b) Describe two instances where an attacker sniffing on a netwo

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