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

What do you meant by the term diffusion and confusion, Question: (a) W...

Question: (a) What do you meant by the term diffusion and confusion? Explain how diffusion and confusion can be implemented. (b) Distinguish between authorisation and auth

Calculate the minimum sampling rate, QUESTION An analog sensor is used...

QUESTION An analog sensor is used to monitor the temperature of sea water at different depth. The sensor is fitted to a buoy and incorporates a wireless transmitter that send

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

Military and space technology, crack the secret message and explain how the...

crack the secret message and explain how the code works. The clue is that it has something to do with the computer keyboard. J-Q-H-6 Q-E-F-Q-H-D-3-W 8-H 5-Y-3 7-W-3 9-R--D-9-J

Explain the schemes for distribution of public keys, (a) What is a pseudora...

(a) What is a pseudorandom generator? Give an example describing how it works. (b) Explain the key components of a wireless network and their purpose. (c) Describe the authen

Network-based ids (nids), Network-Based IDS (NIDS) A NIDS resides on com...

Network-Based IDS (NIDS) A NIDS resides on computer or appliance connected to segment of an organization’s network and looks for signs of attacks. While examining packets, a NID

Lan topologies, Network can be distinguished by shape. According to which t...

Network can be distinguished by shape. According to which there are three most popular methodologies, which are shown as follows; Star Ring Bus

Data compression and the transport services, Da t a compre s sion a...

Da t a compre s sion and the trans p ort s e rvices,   The main purpose of the transport layer is to provide services which are efficient, reliable and cost-effecti

Parsing ipv6 headers, PARSING IPv6 HEADERS Base header is fixed in siz...

PARSING IPv6 HEADERS Base header is fixed in size i.e. 40 octets. NEXT HEADER field in the base header describe kind of header and it seems at end of fixed-size base header. S

Explain the dimension of service quality, Problem 1: Discuss how TWO of...

Problem 1: Discuss how TWO of the following gurus have contributed to the Quality Movement, highlighting the major points of their philosophies: (a) Edward Deming (b) Jose

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