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

Derive the transmitted crc header checksum, QUESTION (a) Consider the f...

QUESTION (a) Consider the following digital bit stream 01001100 is to be encoded in: i. NRZ-I ii. Pseudoternary iii. Manchester iv. Differential Manchester Show th

How will network datagrams be protected at network layer, (a) Consider the...

(a) Consider the subsequent authentication options: A. Using password. B. Using pin and fingerprint Which option A or B provides stronger security and why? (b) Give

Web accessibility initiative standards, Australian government sites were ma...

Australian government sites were mandated to conform to at least single 'A' level of the World Wide Web Consortium (W3C) Web Accessibility Initiative (WAI) standards, by the end of

Udp encapsulation, UDP ENCAPSULATION As given in the figure below, UDP...

UDP ENCAPSULATION As given in the figure below, UDP packet is included in IP datagram and the IP datagram is then attached in the Frame.

Token ring, TOKEN RING Many LAN methods that are ring topology need to...

TOKEN RING Many LAN methods that are ring topology need token passing for synchronized access to the ring. The ring itself is acts as a single shared communication phase. Both

Logic bombs - attacks information security, Example 3: Logic bombs In th...

Example 3: Logic bombs In the year 2000, Timothy Lloyd was found responsible of causing $10 million and $12 million of damage to Omega Engineering, an American company specializ

Define full-duplex., A  full-duplex (FDX) , accepts communication in both...

A  full-duplex (FDX) , accepts communication in both ways, and, unlike half-duplex, accept this to occur simultaneously. Land-line telephone networks are full-duplex, since they

Describe the five-layer network using block diagrams, Problem 1: a) One...

Problem 1: a) One of the limitations of file processing systems is data inconsistency. Briefly explain with the help of an example what do you understand by this phrase. b)

What is the maximum achievable data rate, Question: a) How many bits pe...

Question: a) How many bits per second can be sent on a noiseless 4 MHz channel if four-level digital signals are used? b) If a binary signal is sent over a 3 KHz channel who

Attacks on cryptosystems-cryptography, Attacks on Cryptosystems Attacks a...

Attacks on Cryptosystems Attacks are attempts to achieve unauthorized access to secure communications have characteristically used brute force attacks. Attacker may alternatively

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