1. In the Theta step function, which is a substitution step, each bit value changes. Each bit is dependent on _________ other bits for its new value.

a) 13

b) 4

c) 7

d) 11

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2. Which step function provides most amount of diffusion for the Keccak iteration step?

a) Theta

b) Rho

c) Pi

d) Chi

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3. The Pi step function can be written as-

a) (x, y) × (y, (x + y))

b) (x, y) × (y, (2x + 3y))

c) (x, 2y) × (y, (2x + 3y))

d) (x, 2y) × (y, (x + y))

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4. The CHI step involves which of the following gate operations?

a) AND and NAND

b) AND and XOR

c) XOR and NAND

d) XOR and XNOR

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5. Which matrix is used in the Rho/ Pi steps?

a) [(1 2 | 3 4)]^{t}

b) [(0 2 | 1 4)]^{t}

c) [(0 1 | 2 3)]^{t}

d) [(1 3 | 2 4)]^{t}

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^{t}is used to find the new (x, y) co-ordinates in the Rho/Pi function.

6. What are the new co-ordinates for (x, y) in the Rho step for t =3?

a) (1, 7)

b) (1, 4)

c) (3, 2)

d) none of the mentioned

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^{3}+ (1 , 0 ) gives the answer.

7. The Rho function is defined as : a[x, y, z] ← a[x, y, z-g(t)], where g(t) is defined as

a) (t+1)(t+2)/2

b) (t+1)(t-2)/2

c) (t-1)(t-2)/2

d) (t-1)(t+2)/2

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8. The Chi function is defined as

a) a[x] ← a[x] XOR ( a[x + 1]XOR 1) AND a[x+2])

b) a[x] ← a[x] AND ( a[x + 1]XOR 1) AND a[x+2])

c) a[x] ← a[x] AND ( a[x + 1] XOR a[x+2])

d) a[x] ← a[x] XOR ( a[x + 1] AND a[x+2])

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9. In SHA-3, the Iota step function has a round constant which only works on the last lane.

a) True

b) False

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10. Which is the only step function that provides non-linear mapping?

a) Theta

b) Rho

c) Pi

d) Chi

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11. How many bit positions are active and can affect L[0, 0] in the Iota step function?

a) 8

b) 12

c) 6

d) 7