Find the possible deciphering transformations, Computer Network Security

Assignment Help:

Question:

(a) A string of ciphertext was enciphered using an a±ne transformation of single letters in a 28-letter alphabet consisting of A to Z, a blank and a?, where A to Z have numerical equivalents 0 to 25, blank=26, ?=27. A frequency analysis reveals that the the first, second and third most common letters of this ciphertext are B, ? and I, respectively. Suppose that the first and second most common letters in an English language text written in this 28-letter alphabet are ` '(blank) and E, respectively.

(i) Find the possible deciphering transformations.

(ii) Using the fact that T, is the third most common letter in the English language (of our 28 letters), find the right deciphering transformation.

(b) The ciphertext

¡GSTMTSI XJMUIGHRFKYMV

was generated using a 2£2 enciphering matrix with a 29¡letter alphabet, where A to Z have numerical equivalents 0 to 25, blank=26, !=27, and ¡ = 28. Given that the last five letters of the plaintext are A¡ONE, determine the complete plaintext.


Related Discussions:- Find the possible deciphering transformations

Find the capacity of the wcdma, Question: (a) Describe the term interfe...

Question: (a) Describe the term interference in the space, time, frequency, and code domain. (b) Consider a 1 G - AMPS: 824-849 MHz (forward) ; 869-894 MHz (reverse). B

Computer adaptive test, Project Name : Computer Adaptive Test Role ...

Project Name : Computer Adaptive Test Role : Day to Day interaction with Client. Involved in Requirement Gathering, Estimation.Involved with Stellent design and architectur

#title.TIPS., 1. For this project, assume that an organization has five ser...

1. For this project, assume that an organization has five servers. Server 1 has a TCO of $25,000, Servers 2 and 3 have a TCO of $37,000 each, and the remaining two servers— Servers

Star topology, In Star topology all computers are connected using a cen...

In Star topology all computers are connected using a central device known as hub. Star networks are one of the most general computer network topologies. In its simplest way, a

Secure a wireless network, Secure a Wireless Network WIRELES Most onli...

Secure a Wireless Network WIRELES Most online retailers provide some type of privacy statement. Many statements are long, and appear in small print, and many appear to be simi

What is the main security vulnerability of ipv4, Question: (a) What is...

Question: (a) What is the main security vulnerability of IPv4? (b) Which protocol can be used for secure remote login? (c) Distinguish between the transport and tunnel

Plain-text using play-fair encryption, What is one-time pad for encryp...

What is one-time pad for encryption?  Describe how it offers both Confusion and Diffusion. Using the letter encoding discussed in class (along with one-time

Emulation, In this section, you should create a program that emulates a GBN...

In this section, you should create a program that emulates a GBN node. Two GBN nodes will be running to send packets to each other through the UDP protocol. For emulation purpose,

How an attacker can effectively de-layer and analyse data, Around the globe...

Around the globe the bank controlled Co-ops (Visa, MasterCard, Discover, and American Express) have rolled out millions of smart cards under the EMV (Europay, MasterCard, VISA) sta

Protocols for secure communications-cryptography, Protocols for Secure Comm...

Protocols for Secure Communications Securing Internet Communication by using S-HTTP and SSL Secure Socket Layer (SSL) protocol is a protocol that uses public key encryption t

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