Symmetric Ciphers Questions and Answers – Polynomial and Modular Arithmetic- I

«
»

This set of Cryptography Multiple Choice Questions & Answers (MCQs) focuses on “Polynomial and Modular Arithmetic”.

1. A very common field in this category is GF(2) with the set {1, 2} and two operations, addition and multiplication.
a) True
b) False
View Answer

Answer: b
Explanation: GF(2) is the set {0, 1} with two operations, addition and multiplication

2. Multiplication / Division follow which operation?
a) XOR
b) NAND
c) AND
d) OR
View Answer

Answer: c
Explanation: Multiplication / Division is the same as the AND operations.

3. What do the above numbers correspond to?
0 1 2 3 4
0 4 3 2 1

Note: Join free Sanfoundry classes at Telegram or Youtube
advertisement
advertisement

0 1 2 3 4
– 1 3 2 4

a) Both Additive Inverses
b) Both Multiplicative Inverses
c) Additive and Multiplicative Inverse respectively
d) Multiplicative and Additive Inverses respectively
View Answer

Answer: b
Explanation: The top set of numbers correspond to Additive Inverses and the bottom set of numbers correspond to Multiplicative Inverse.

4. How many numbers cannot be used in GF(p) in 2n where n=4?
a) 2
b) 5
c) 3
d) 1
View Answer

Answer: c
Explanation: If n=4, the largest prime less than 24 is 13. This means that we cannot use the integers 13, 14 and 15.

5. If f(x)=x3+x2+2 and g(x)=x2-x+1, find: f(x) + g(x)
a) x3+2x2-x+3
b) x3+x2+3
c) x3+x+1
d) x2+2x+4
View Answer

Answer: a
Explanation: We get the solutions via basic polynomial addition.
advertisement

6. If f(x)=x3+x2+2 and g(x)=x2-x+1, find: f(x) – g(x)
a) x3+x+4
b) x3+x+1
c) x3+x2+3
d) x3+3x+2
View Answer

Answer: b
Explanation: We get the solutions via basic polynomial subtraction.

7. If f(x)=x4+x3+2 and g(x)=x3-x+6, find: f(x) + g(x)
a) 2x4+2x3+x+8
b) x4+2x3-x+8
c) x4+x2+x+8
d) x4+x3+8
View Answer

Answer: b
Explanation: Perform polynomial addition.
advertisement

8. If f(x)=x4+x2-x+2 and g(x)=x2-x+1, find: f(x) – g(x)
a) x4+1
b) x2+1
c) x2+2x+6
d) x4-1
View Answer

Answer: a
Explanation: Perform polynomial subtraction.

9. If f(x)=x3+x2+2 and g(x)=x2-x+1, find the quotient of f(x) / g(x)
a) x+3
b) x2+4
c) x
d) x+2
View Answer

Answer: d
Explanation:We get the solution via basic polynomial division.

10. If f(x)=x3+x2+2 and g(x)=x2-x+1, find: f(x) x g(x)
a) x4+x2+2x+2
b) x5+2x3+2x+3
c) x5+3x2-2x+2
d) x4+x2+x+1
View Answer

Answer: c
Explanation: We get the solution via basic polynomial multiplication.

11. Find the 8-bit word related to the polynomial x5 + x2 + x
a) 00010011
b) 01000110
c) 00100110
d) 11001010
View Answer

Answer: c
Explanation: The respective 8-bit word is 00100110.

12. Find the 8-bit word related to the polynomial x6 + x5 + x2 + x +1
a) 00010011
b) 11000110
c) 00100110
d) 01100111
View Answer

Answer: d
Explanation: The respective 8-bit word is 01100111.

Sanfoundry Global Education & Learning Series – Cryptography and Network Security.

To practice all areas of Cryptography and Network Security, here is complete set of 1000+ Multiple Choice Questions and Answers.

advertisement
advertisement
Subscribe to our Newsletters (Subject-wise). Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

Youtube | Telegram | LinkedIn | Instagram | Facebook | Twitter | Pinterest
Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

Subscribe to his free Masterclasses at Youtube & discussions at Telegram SanfoundryClasses.