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

Computer fundamentals, Ask You have been asked by a new client to assist i...

Ask You have been asked by a new client to assist in setting up a new computer for her coffee shop. She has just purchased the newest Apple computer from an online site. Should wou

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

What is the use of digital certificate, Question: (a) What is the use ...

Question: (a) What is the use of digital certificate? (b) What is meant by a hierarchical trust model in a Public Key Infrastructure? How does the Pretty Good Privacy (PG

Intrusion detection and classification, i want to detec and classify networ...

i want to detec and classify network anomaly detection based on KDD99 data set using swarm intelligence

Transmission errors in networking, TRANSMISSION ERRORS:  Transmission...

TRANSMISSION ERRORS:  Transmission exceptions may happen due to different causes for example power surges or interference may delete data during transmission. In result of wh

Operation of the signature based intrusion detection system, Question : ...

Question : (a) State whether the following statement is FALSE or TRUE: It is always better to have various access points to the Internet so that if a hacker takes one down you

What is data spoliation, QUESTION (a) What do you meant by data spoli...

QUESTION (a) What do you meant by data spoliation? (b) Justify the following statement: "Disk imaging differs from creating a standard backup of disk." (c) Why do yo

Explain symmetric and asymmetric encryption system, Question 1: (a) Dif...

Question 1: (a) Differentiate between symmetric and asymmetric encryption system. (b) Describe how a digital signature is created. (c) Explain briefly what SSL (secure so

The major decision hierarchy for disclosing security problem, QUESTION ...

QUESTION The major decision hierarchy for disclosing security problems is if the problem is with the product owned by the business or if it is used by the business. Although th

Does ssl protect against eavesdropping, QUESTION (a) Consider the follo...

QUESTION (a) Consider the following authentication options A. Using password B. Using pin and fingerprint Which option A or B provides stronger security and why? (b

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