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

Why is this setup not secure, Question: a) You are using Active Directo...

Question: a) You are using Active Directory Users under Windows Server 2003 and Computers to configure user objects in your domain, and you are able to change the address and

Perimeter Network Security System coursework, what is the guaranteed qualit...

what is the guaranteed quality of this coursework? how many days it take for 10-12 pages? how much will be? thanks

Layering, ADDRESS RESOLUTION AND PROTOCOL ADDRESSES Address resolution...

ADDRESS RESOLUTION AND PROTOCOL ADDRESSES Address resolution (ARP) is a network interface layer protocol. Protocol addresses are used in all upper layers. Address resolution s

Factors of informtion security, Confidentiality Confidentiality of inform...

Confidentiality Confidentiality of information ensures that only those with sufficient privileges may access specific information. When unauthorized individuals can access inform

Collision, COLLISION: The receiver can get simultaneous requests, which gi...

COLLISION: The receiver can get simultaneous requests, which gives in collision at receivers and both service lost and in this way no transmitter accepts reservations and both use

Base lining-information security, Base lining •    Organizations do not ...

Base lining •    Organizations do not have any contact to each other •    No two organizations are identical to each other •    The best practices are a moving target •    K

Point-to-point topology, POINT-TO-POINT: In Point-to-Point topology th...

POINT-TO-POINT: In Point-to-Point topology there are two kind of topologies. 1) STAR topology 2) TREE topology In star topology each and every computer is connect

Computer security incident response team, QUESTION 1 Using a real life ...

QUESTION 1 Using a real life scenario or context list and set the scene for at least four advantages that an organized incident response program promotes. QUESTION 2 Yo

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

Network security attacks, (a) Show four Network Security attacks. How do th...

(a) Show four Network Security attacks. How do they compromise security? (b) In what ways do the following devices or services contribute to security: (i) Firewall (ii) In

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