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

Evaluate the percentage availability of the network, QUESTION a) "Two ...

QUESTION a) "Two of the key attributes of an enterprise network is that it have to be multi-platform and multisite." Decribe what you understand by this statement. b) A

What is meant by certificate revocation, QUESTION (a) Which PKI (Public...

QUESTION (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 certi

Explain transposition ciphers and substitution cipher, What do you understa...

What do you understand by cryptanalysis? Discuss about the transposition ciphers substitution cipher, and onetime pads. The messages which are intended to transmit secretly and

Virtual packets, VIRTUAL PACKETS These data packets serve same reason ...

VIRTUAL PACKETS These data packets serve same reason in Internet as frames on LAN. Every packet has a header. Routers, which are normally gateways, transfer packets between ph

Describe types of communication impairments, Question : (a) "Pulse Code...

Question : (a) "Pulse Code Modulation (PCM), as used in telephony, samples a signal at 8 kHz using 256 quantization levels". Outline how this scheme works with the help of ske

Secure clustering in WSNs, i have an idea of clustering in wsns . where eac...

i have an idea of clustering in wsns . where each and every sensor node use the reputation scheme and while clustering provide help against the selfishness atatck of the sensor nod

What is a firewall, QUESTION (a) Define and distinguish between Electro...

QUESTION (a) Define and distinguish between Electronic Commerce and Electronic Business (b) According to you what are the benefits that Electronic Commerce can brings to org

Locality of reference , LOCALITY OF REFERENCE PRINCIPLE:  Principle of...

LOCALITY OF REFERENCE PRINCIPLE:  Principle of "Locality of Reference" use to predict computer interaction patterns. There are two patterns shown as follows: a) Spatial loca

What are the main objectives of a risk analysis, QUESTION 1 Risk ana...

QUESTION 1 Risk analysis helps companies prioritize their risks and shows management the amount of money that should be applied to protecting against those risks in a sensib

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

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