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

Wireless networks, Wireless Networks The origin of wireless networks a...

Wireless Networks The origin of wireless networks and their ubiquity in the technological environment poses a new type of exposure and vulnerability for network security. Cont

CNSS Security model, "Using the CNSS Model, examine each of the cells and w...

"Using the CNSS Model, examine each of the cells and write a brief statement on how you would address the components respesented in that cell"

Explain how the diffie-hellman key agreement protocol works, (a) Using Fer...

(a) Using Fermat's theorem, find 3 201 mod 11. (b) Explain how the Diffie-Hellman key agreement protocol works and what its purpose and main properties are. Consider a Dif

Computer security, For this assessment, students must research and analyse ...

For this assessment, students must research and analyse two different scenarios. The two scenarios must be chosen from those described below and submitted as one Microsoft PowerPoi

Elliptic Curves, #questioAn elliptic curve y^2=x^3+ax+b(mod29) includes poi...

#questioAn elliptic curve y^2=x^3+ax+b(mod29) includes points P=(7, 15) and Q=(16, 13) a)Determine the equation of the crve b) Determine all values of x for which there is no point

Management of classified data-risk management, Management of Classified Dat...

Management of Classified Data Management of classified data comprises of its storage, distribution, portability, and destruction of classified data. All information which is not

Use the chinese remainder theorem to evaluate x, Use the Chinese remainder ...

Use the Chinese remainder theorem to evaluate x from the following simultaneous congruences: x ≡ 1 (mod 2); x ≡ 2 (mod 3); x ≡ 3 (mod 5). Calculate gcd(14526, 2568). (

Describe the function of a tap in wmns, Question: (a) A Wireless Mesh N...

Question: (a) A Wireless Mesh Network (WMN) is a communications network made up of radio nodes organized in a mesh topology. i. Describe the function of a TAP in WMNs. ii.

Define checksum, The method used to check errors is checksum . In this m...

The method used to check errors is checksum . In this method data is treated as a sequence of integers and their arithmetic sum is calculated and the carry bits are added to the

Major difference between a virus and a worm, Question: (a) State wheth...

Question: (a) State whether the following statements are TRUE or FALSE. Justify your answer. i. A good site security policy will require that users use computer generated p

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