Complete the following truth table: f denotes false and t denotes true

Q1a     Complete the following Truth Table: F denotes false and T denotes True



C=A or B

D= A xor B

E= A and B






















Q1b In the following Θ denotes one of the following operators: ’or’, ‘xor’ or ‘and’.

Input1 Θ input2 = Result   where, input1, 2 are ‘A’ and ‘B’ and Result is one of C, D, or E.

which operation will yield

input1(2) Θ result = input 2(1)


Q2       Using the English alphabet (i.e., mod 26 arithmetic) let plaintext = {p1, p2,… ,pn} and corresponding ciphertext = {c1, c2,… , cn}.

Suppose the encryption function is ci = pi + 10 (mod 26).  You receive the ciphertext message EWEM SC K QBOKD CMRYYV

What is the decryption function, and the decrypted/recovered plaintext? What type of cipher is this? Show your calculations.


Q3       You are Alice. You have agreed with your friend Bob that you will use the Diffie-Hellman public-key algorithm to exchange secret keys. You and Bob have agreed to use the public base g = 3 and public modulus p = 809.

You have secretly picked the value SA = 17. You begin the session by sending Bob your calculated value of TA. Bob responds by sending you the value TB = 291. 

What is the value of your shared secret key? Can you guess Bob’s secret value SB and what it would be? Show steps of your calculations


Q4       Bob believes that he has come up with a nifty hash function. He assigns a numeric value VChar to each letter in the alphabet equal to the letter’s position in the alphabet, i.e., VA = 1, VB = 2, …, VZ = 26. For a message, he calculates the hash value H = (VChar 1 x VChar 2 x VChar 3 …x VChar N) mod(26).

Bob uses this function to send a one-word message, REGAL, to his banker Bill, along with his calculated hash value for the message. Alice is able to intercept the message, and generates an alternative message that has a hash value that collides with Bob’s original hash value.

Give definition and properties of the hash function.

Show a message that Alice may have used to spoof Bob’s message, and demonstrate that its hash value collides with Bob’s original hash.


Q5       Consider the following plaintext message: THE SIXTEENTH PRESIDENT WAS ABRAHAM LINCOLN.

a.       (3 pts) If this message is sent unencrypted and successfully received, what is its entropy? And why?

b.      (3 pts) If this message is encrypted with DES using a random 56-bit key, what is the encrypted message’s entropy?  And why


Q6 Compare and contrast symmetric and asymmetric encryption algorithms.

·         Your response should include a brief overview of the cryptographic basis for each type of algorithm, and a comparison of their relative strengths and vulnerabilities.

·         Describe how a hacker might go about cracking a message encrypted with each type of algorithm. 

·         Suggest a specific application for each type of algorithm where the advantages clearly outweigh the disadvantages.

·         Remember to address all points




Calculate Your Essay Price
(550 words)

Approximate price: $22

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
The price is based on these factors:
Academic level
Number of pages
Basic features
  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support
On-demand options
  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading
Paper format
  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Our guarantees

Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

Read more

Zero-plagiarism guarantee

Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.

Read more

Free-revision policy

Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.

Read more

Privacy policy

Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.

Read more

Fair-cooperation guarantee

By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.

Read more

Enjoy 10% OFF today with the coupon code: best10