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

Using Technology as Experience Framework, Write a two to three (2-3) page p...

Write a two to three (2-3) page paper in which you: Explain how the Web user interfaces help donors to make decisions. Relate the emotional thread demonstrated in the case study to

Categories of controls-information security, Categories of Controls Cont...

Categories of Controls Controlling risk through mitigation, avoidance or transference is accomplished by implementing controls. There are 4 effective approaches to select the co

Risk control strategies-, Risk Control Strategies Once the ranked vulner...

Risk Control Strategies Once the ranked vulnerability risk worksheet has created, they should choose one of following 4 strategies to control each risk: •Apply safeguards which

Ids response behavior, IDS RESPONSE BEHAVIOR Once IDS detects an anomalo...

IDS RESPONSE BEHAVIOR Once IDS detects an anomalous network situation, it has a number of options. IDS responses to external stimulation can be classified as active or passive.

Http protocol, Question (a) Name 3 popular electronic mail access prot...

Question (a) Name 3 popular electronic mail access protocols? (b) i. What is DNS? ii. Briefly, describe what it does and how it works? iii. Why does DNS use a dist

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

Local talk, LOCAL TALK Apple discovered the LAN technology that uses b...

LOCAL TALK Apple discovered the LAN technology that uses bus topology. Its interface is added with all Macintosh computers. It has very low speed i.e. 230.4Kbps. Also it is ch

Application-based ids, Application-Based IDS Application-based IDS (AppI...

Application-Based IDS Application-based IDS (AppIDS) is an advanced version of HIDS. It examines application for abnormal events. The ability to view encrypted data is the uniqu

The Security Systems Development Life Cycle (SecSDLCtle.., #Under what circ...

#Under what circumstances would the use of a SecSDLC be more appropriate than an SDLC?

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