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

Cryptography, hi have a look and tell me if u can do it. if u can do Q1then...

hi have a look and tell me if u can do it. if u can do Q1then i will allow u to do Q2

Hardware, Hardware, Software, and Network Asset Identification What info...

Hardware, Software, and Network Asset Identification What information attributes to track is dependent on: •    Requires of organization/risk management efforts •    Management

Algorithm, algorithm on simple intrest

algorithm on simple intrest

Cipher methods-cryptography, Cipher Methods There are 2 methods of encry...

Cipher Methods There are 2 methods of encrypting plaintext: • Bit stream method – every bit in the plaintext bit is transformed into a cipher bit one bit at a time. • Block cip

Determine the round trip time, QUESTION a) Determine the RTT (round tr...

QUESTION a) Determine the RTT (round trip time) between a client requesting a web page of 1024 bytes in size from an internal web server on a 100 Base-T Ethernet. Consider a o

Steganography-cryptography, Steganography It is a process of hiding info...

Steganography It is a process of hiding information in use for a long time. Most popular modern version of this process hides information within files appearing to contain digit

Ip address, How to find an ip address?

How to find an ip address?

Basic functions of e-mail system, B a s i c functions of e-mail system ...

B a s i c functions of e-mail system are given as follows: C o mp o sition refers to the procedure of creating messages and the answers. Though any text editor can be

Cyclic redundancy check (crc), CYCLIC REDUNDANCY CHECK (CRC) To activa...

CYCLIC REDUNDANCY CHECK (CRC) To activate a network system to check move error without increasing the amount of information in every packet another most successful method is 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

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