Q. 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?

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Q. 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?

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Q. P = C1 – (d x C2)

Is this above stated formula true with respect to ECC?

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

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

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Q. When a hash function is used to provide message authentication, the hash function value is referred to as

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Q. Message authentication code is also known as

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Q. The main difference in MACs and digital signatures is that, in digital signatures the hash value of the message is encrypted with a user’s public key.

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Q. What is a one-way password file?

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Q. Which one of the following is not an application hash functions?

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Q. If the compression function is collision resistant, then so is the resultant iterated hash function.

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Q. A larger hash code cannot be decomposed into independent subcodes.

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Q. We define collision as: A collision occurs if we have x=y and H(x) = H(y).

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Q. Consider the following properties:

Variable Input size
Fixed Output size
Efficiency
Pre image resistant
Second Pre image Resistant
Collision resistant
Pseudo randomness

A has function that satisfies the first _______ properties in the above table is referred to as a weak hash function.

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Q. A function that is second pre-image resistant is also collision resistant.

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Q. Which attack requires the least effort/computations?

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Q. SHA-1 produces a hash value of

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Q. What is the number of round computation steps in the SHA-256 algorithm?

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Q. In SHA-512, the message is divided into blocks of size ___ bits for the hash computation.

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Q. What is the maximum length of the message (in bits) that can be taken by SHA-512?

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