This set of Cryptography online quiz focuses on “Elliptic Curve Arithmetic/Cryptography”.

1. On adding the two points P (4,2) and Q (10, 6) in the elliptic curve E11(1,1) we get

a) (9,3)

b) (6,4)

c) (7,5)

d) (2,8)

View Answer

Explanation: Apply ECC to obtain P+Q=(6,4).

2. If P = (1,4) in the elliptic curve E13(1, 1) , then 4P is

a) (4, 2)

b) (7, 0)

c) (5, 1)

d) (8, 1)

View Answer

Explanation: Apply ECC via adding P+P=2P then, 4P=2P+2P.

3. Multiply the point P=(8, 1) by a constant 3, thus find 3P, in the elliptic curve E13(1, 1)

a) (10,7)

b) (12,6)

c) (11,1)

d) (9,8)

View Answer

Explanation: P+P=2P then, 3P=2P+P

Thus we get Q=3P = (10, 7).

4. Bob selects E67(2, 3) as the elliptic curve over GF(p). He selects e1 = (2, 22) and d = 4.

Then he calculates e2 = d × e1 .What is the value of e2?

a) (23,49)

b) (16,55)

c) (12,19)

d) (13,45)

View Answer

Explanation: e2 = d × e1 ; e2 =(13, 45).

5. Bob selects E67(2, 3) as the elliptic curve over GF(p). He selects e1 = (2, 22) and d = 4.

Then he calculates e2 = d × e1 and the publicly announces the tuple (E, e1, e2). Now, Alice wants to send the plaintext P = (24, 26) to Bob and she selects r = 2. What are C1 and C2?

a) C1=(35,1) ; C2 =(21,44)

b) C1=(44,21) ; C2 =(1,35)

c) C1=(44,21) ; C2 =(44,21)

d) C1=(21,44); C2 =(35,1)

View Answer

Explanation: Alice finds the points C1= r × e1 ; C1= (35, 1),

C2=P + r × e2 ; C2= (21, 44).

6. P = C1 – (d x C2)

Is this above stated formula true with respect to ECC?

a) True

b) False

View Answer

Explanation: P = C2 – (d x C1).

7. For the point P (11, 2) defined in the curve E13(1, 1). What is –P?

a) (12,4)

b) (10,7)

c) (11,11)

d) (11,12)

View Answer

Explanation: The inverse of P(11,2) is (11,11) or (11,-2).

8. For the point P (7, 0) defined in the curve E13(1, 1). What is –P?

a) (7,1)

b) (8,12)

c) (8,1)

d) (7,0)

View Answer

Explanation: The inverse of P(11,2) is (11,11) or (11,-2).

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

To practice all areas of Cryptography for online quizzes, __here is complete set of 1000+ Multiple Choice Questions and Answers__.