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

Calculate the rsa public and private keys, (a) Which PKI (Public Key Infra...

(a) Which PKI (Public Key Infrastructure) model is typically favored by business organization? (b) Give one possible use of the "extensions" field of an X.509 certificate

Explain the random key distribution, Q. Explain the random key distribution...

Q. Explain the random key distribution? The triple key management mechanisms ensure a better and complete security solution using the random key distribution mechanism. In this

Pcm encoder, You have been asked to setup a remote temperature sensing syst...

You have been asked to setup a remote temperature sensing system for an electric furnace. The system consists of a sensor unit which feeds an analogue signal to a PCM encoder. The

What is border gateway protocol, Border Gateway Protocol It is a proto...

Border Gateway Protocol It is a protocol needed to advertise the set of networks that can be achieved within an autonomous machine. BGP activates this information to be shared

Guided media, Guided Media These are those that give a conduit from on...

Guided Media These are those that give a conduit from one machine to another that add twisted-pair, fiber-optic cable and coaxial cable. A signal traveling along any of these

Explain security, W h a t do you understand by the terms security, netwo...

W h a t do you understand by the terms security, network security and information security? How network security and information security are connected? Security can be def

Http protocol, Question (a) Name 3 popular electronic mail access prot...

Question (a) Name 3 popular electronic mail access protocols? (b) i. What is DNS? ii. Briefly, describe what it does and how it works? iii. Why does DNS use a dist

Find the services implemented on your computer, Question: (a) Which typ...

Question: (a) Which type of attacker represents the most likely and most damaging risk to your network? (b) What is the basic reason that social engineering attacks succeed?

Introduction to network protocol, In this assignment, you are required to e...

In this assignment, you are required to emulate the operation of a link layer and network layer protocols in a small computer network. Your program should behave like a single node

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