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

Intercultural sensitivity: recognising differences, Intercultural sensitivi...

Intercultural sensitivity: recognising differences You represent a Mauritian computer company which is negotiating to buy hardware from a manufacturer in Japan. In your first

Cryptographic algorithms-cryptography, Cryptographic algorithms Cryptogr...

Cryptographic algorithms Cryptographic algorithms are broadly classified into two broad categories. They are stated below 1.  Symmetric Encryption and 2.  Asymmetric Encryptio

What is the size of the initialization vector n wpa, Question : Wi-Fi p...

Question : Wi-Fi protected access (WPA) was specified by the Wi-Fi alliance with the primary aim of enhancing the security of existing 802.11 networks. However, WPA was only a

Nyquist capacity theorem, (a) Illustrate what you understand by Nyquist Cap...

(a) Illustrate what you understand by Nyquist Capacity Theorem? (b) Consider we wish to transmit at a rate of 64 kbps over a 4 kHz noisy but error-free channel. What is the mini

Draw the waveform for an asynchronous transmission, QUESTION: (a) For ...

QUESTION: (a) For the bit stream 010011, sketch the waveforms for each of the code indicated. Assume that the signal level for a space in NRZ-L is positive; the signal level f

Bus topology, BUS TOPOLOGY In a bus topology all devices are attached ...

BUS TOPOLOGY In a bus topology all devices are attached to a single long cable and any device can send data to any other device. For this function, coordination is needed to d

Social studies, how would land elevation have canged if coronado had travel...

how would land elevation have canged if coronado had traveled 150 miles due west from what is today arizona instead of west toward new mexico

Routing tables and address masks, ROUTING TABLES AND ADDRESS MASKS Add...

ROUTING TABLES AND ADDRESS MASKS Additional information is saved in routing table. Destination is kept as network address. Next hop is saved as IP address of router. Address m

Address resolution protocol (arp), ADDRESS RESOLUTION PROTOCOL (ARP) T...

ADDRESS RESOLUTION PROTOCOL (ARP) TCP/IP can use any of the three address resolution functions relaying on the addressing procedure used by the underlying hardware. To guarant

Meaning of dns - domain name system, What do you understand by the DNS? Exp...

What do you understand by the DNS? Explain the usage of the resource rec or ds. Domain Name System is described below: The Domain Name Service (DNS) is the hierarchi

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