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

Transport protocols, TRANSPORT PROTOCOLS: Give application-to-appl...

TRANSPORT PROTOCOLS: Give application-to-application communication. Require extended addressing mechanisms to check applications. Are known end-to-end communicatio

Emerging threats related to use of networks, Question requires you to submi...

Question requires you to submit a proposal based on the research report topic you will be addressing in the second assignment.  Note:  before commencing research on the topic, y

Explain about security aware protocols, Q. Explain about Security aware pro...

Q. Explain about Security aware protocols? The security-Aware ad hoc Routing (SAR) protocol based on the security attributes integrated into the ad hoc route discovery provides

RESPONSE, Dropbox’s tool shows how chatbots could be future of cybersecurit...

Dropbox’s tool shows how chatbots could be future of cybersecurity

Configuration for 3des, (a) Explain the two possible configuration for 3DE...

(a) Explain the two possible configuration for 3DES. (b) What is the main disadvantage of 3DES? (c) Why are most modern symmetric algorithm block ciphers? (d) Describe

Determine the round trip time, QUESTION a) Determine the RTT (round tr...

QUESTION a) Determine the RTT (round trip time) between a client requesting a web page of 1024 bytes in size from an internal web server on a 100 Base-T Ethernet. Consider a o

Technology, how can you enter the ASVAB practice test on line?

how can you enter the ASVAB practice test on line?

Network security keys, The three primary types of network protection are th...

The three primary types of network protection are the same as the three primary areas where a network can be attacked. Every network needs protection against people-related, hardwa

Systems development life cycle (sdlc)-information security, SDLC Systems ...

SDLC Systems development life cycle (SDLC) is process of developing information systems through analysis, design, investigation, implementation and maintenance. SDLC is called as

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