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

Access controls-information security, Access Controls Access controls ad...

Access Controls Access controls addresses admission of a user into a trusted area of organization. It comprises of a combination of policies & technologies. The ways to control

Extended euclidean algorithm, (a) Using the extended Euclidean algorithm, ...

(a) Using the extended Euclidean algorithm, find the multiplicative inverse of 504 mod 67. (b) Decrypt the following ciphertext, which has been encrypted using Caesar cipher:

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

Describe the use of control channels in gsm network, Problem 1: What is...

Problem 1: What is the function of AUC in the GSM architecture? Explanation of HLR(AUC) Architecture of GSM Problem 2: Show the layered architecture of t

Feasibility studies-risk management, Feasibility Studies Before deciding...

Feasibility Studies Before deciding on strategy, all information of economic or non economic consequences of vulnerability of information asset should be explored. A number of w

Develop a completely secure wsn based on the triple key, Q. Develop a compl...

Q. Develop a completely secure WSN based on the triple key? Wireless network is the most vulnerable type of network to security attack. Unauthorized access to wireless network

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

Evaluate the sample correlation between y and z, Question: (a) Data on ...

Question: (a) Data on four variables are stored in a file called file1.dat. The first line of the file is the variable names f, x, y and z. Give the R commands to (i) read t

Star topology, STAR TOPOLOGY In this topology, all devices are attache...

STAR TOPOLOGY In this topology, all devices are attached to a central point, which is sometimes known as the "Hub" as given in the diagram below.   Figure: An ideal

Intrusion detection and classification, i want to detec and classify networ...

i want to detec and classify network anomaly detection based on KDD99 data set using swarm intelligence

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