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

Typical network management system, Problem 1: List measurable entities ...

Problem 1: List measurable entities on which the quality of service in a data communication network depends Problem 2: Show the features of a typical Network Management

Cyber security - vulnerabilities, The world has to deal with newly released...

The world has to deal with newly released vulnerabilities on a daily basis.  These vulnerabilities eventually lead to active exploits of systems, and it is our job as cyber securit

Security and basics steps in writing thesis, how can i start thesis? Please...

how can i start thesis? Please mention so of examples?

Define packet, CONCEPT OF PACKET : Network systems splits data in small ...

CONCEPT OF PACKET : Network systems splits data in small junks or blocks known as packets, which they send individually. Why we required packets rather than bits? The answer to

What you understand by the term brute force attack, Question: a) Expla...

Question: a) Explain what you understand by the term brute force attack, giving an example of such an attack b) Briefly outline the concept of Caesar cipher and identify a

Develop firewall rules, Question requires you to develop firewall rules bas...

Question requires you to develop firewall rules based on a fictitious organisation. Scenario: You work for a security-conscious company, xC-Cure, who develop encryption tec

Web accessibility initiative standards, Australian government sites were ma...

Australian government sites were mandated to conform to at least single 'A' level of the World Wide Web Consortium (W3C) Web Accessibility Initiative (WAI) standards, by the end of

Explain the dimension of service quality, Problem 1: Discuss how TWO of...

Problem 1: Discuss how TWO of the following gurus have contributed to the Quality Movement, highlighting the major points of their philosophies: (a) Edward Deming (b) Jose

Computer Security, I have an assignment of Computer Security to submit. Wil...

I have an assignment of Computer Security to submit. Will you guys help me making my assignment???

Ethernet network, QUESTION : a) A datagram of 3000 bytes has to travel...

QUESTION : a) A datagram of 3000 bytes has to travel over a network with a MTU size of 1000 bytes. Describe how fragmentation can be used to solve this problem. You should pr

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