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

Base lining-risk management, Base lining •    Organizations do not have ...

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

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

Types of errors detection in crc , CRC can detect the following errors bett...

CRC can detect the following errors better than check sums. a) Vertical errors b) Burst errors a) VERTICAL ERRORS:  This kind of error happens due to a hardware fai

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

For providing the security, There are various benefits related with providi...

There are various benefits related with providing the security. They are given below,  (i)  Confidentiality/ Privacy (ii)  Integrity  (iii) Availability (iv)Authenticatio

Trap and trace systems-information security, TRAP AND TRACE SYSTEMS Trap...

TRAP AND TRACE SYSTEMS Trap and Trace Systems use techniques to detect an intrusion and trace it back to its source. Trap comprises of honey pot or padded cell and alarm. The dr

Programming, SDES encryption and decryption

SDES encryption and decryption

Incident response, Incident Response: Complete the following sections as id...

Incident Response: Complete the following sections as identified from your Incident Response template (in MS Word format): Update the table of contents (autogenerated) Separate

What is information-information security, What is information Informatio...

What is information Information comprises the meanings and interpretations which people place upon the facts, or data. The value of information springs from the ways it can be i

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