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

Cryptographic hash functions, (a) (i) Bob has public RSA key (n = 77, e...

(a) (i) Bob has public RSA key (n = 77, e = 7). Show that Bob's private key is (d = 43). (ii) Alice wants to send the message m = 13 to Bob. She encrypts the message usi

Network security course work, doing coursework in Network Security to prese...

doing coursework in Network Security to present a possible solution to the problem at hand by creating a prototype of the new network security infrastructure. This new design shou

Elliptic Curves, #questioAn elliptic curve y^2=x^3+ax+b(mod29) includes poi...

#questioAn elliptic curve y^2=x^3+ax+b(mod29) includes points P=(7, 15) and Q=(16, 13) a)Determine the equation of the crve b) Determine all values of x for which there is no point

Calculate the total latency, Question (a) Inspect the following ifconfi...

Question (a) Inspect the following ifconfig output of an IPv6 interface: i. What is the hidden Hardware Address of the interface on Line #1? ii. What is the hidden subn

How to create a security policy, Five years ago, Calgary Kids' Cloth Ltd wa...

Five years ago, Calgary Kids' Cloth Ltd was just a small retail store in downtown Calgary. The company started their own factory in SE Calgary to produce outdoor clothes for kids.

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

Example of a public key algorithm, Question : (a) There are two approa...

Question : (a) There are two approaches for providing confidentiality for packets in a network using symmetric encryption: End-to-End Encryption and Link Encryption. State wh

Direct point-to-point communication:, Early networks used simple point-to...

Early networks used simple point-to-point communication . In such a method of communication every communication channel connects exactly two devices. In this way it prepares a m

Uc, every time i connect to WIFI the UC goes directly to 100% then i doesn'...

every time i connect to WIFI the UC goes directly to 100% then i doesn''t want to come down. what shall i do ?

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