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

Ipv6 addressing, IPv6 ADDRESSING IPv6 has 128-bit addresses. A 128-bit...

IPv6 ADDRESSING IPv6 has 128-bit addresses. A 128-bit address adds network prefix and host suffix. An benefit of IPv6 addressing is that there is address classes i.e. prefix/s

Define packet, CONCEPT OF PACKET : Network systems splits data in small ...

CONCEPT OF PACKET : Network systems splits data in small junks or blocks known as packets, which they send individually. Why we required packets rather than bits? The answer to

Network protocol hierarchy , This assignment aims to enhance students' unde...

This assignment aims to enhance students' understanding of the network protocol hierarchy and flow control and error control techniques by implementing a sliding window protocol in

Security goals, what is relation ship between computer security goals?

what is relation ship between computer security goals?

Produce a packet from a wireshark capture, Question requires you to produce...

Question requires you to produce a pcap file from a Wireshark capture.  In addition, you must include a screen capture of Wireshark and some specific information regarding the fram

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:

Define checksum, The method used to check errors is checksum . In this m...

The method used to check errors is checksum . In this method data is treated as a sequence of integers and their arithmetic sum is calculated and the carry bits are added to the

Explain how ethernet deals with collisions, (a) Describe how CSMA/CD operat...

(a) Describe how CSMA/CD operates and explain how Ethernet deals with collisions. (b) Describe how the subsequent protocols work: i. ARP ii. DHCP iii. DNS iv. SMTP (c) The

Datagram reassembly, DATAGRAM REASSEMBLY Recreation of original datagr...

DATAGRAM REASSEMBLY Recreation of original datagram is known as reassembly. Ultimate receiver acts reassembly as given below.Fragments can reach out of order. Header bit check

Introduction to risk management and its component, INTRODUCTION TO RISK MAN...

INTRODUCTION TO RISK MANAGEMENT Risk management is the procedure of identifying and controlling risks facing an organization. Risk management is the discipline which is employed

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