This set of Cryptography Multiple Choice Questions & Answers (MCQs) focuses on “Secure Hash Algorithms (SHA) – 3”.

1. In SHA-3, which step function does the operation L[2,3] <- L[2,3] XOR NOT(L[3,3]) AND L[4,3] represent?

a) Theta

b) Rho

c) Pi

d) Chi

View Answer

Explanation: The above operation represents the chi step function.

2. In SHA-3, which function does the operation L[2,3]<- C[1] XOR L[2,3] XOR ROT(C[3],1) represent?

a) Theta

b) Rho

c) Pi

d) Chi

View Answer

Explanation: The above operation represents the theta step function.

3. How many rounds are present in each iteration function of SHA-3?

a) 3

b) 4

c) 5

d) 6

View Answer

Explanation:Each Iteration of the SHA-3 algorithm has 5 step functions.

4. In SHA-3, which step function does not affect W [0, 0]?

a) Theta

b) Iota

c) Pi

d) Chi

View Answer

Explanation: Pi and Rho step functions do not cause any change on W [0, 0].

5. Which among the following is not a substitution operation?

a) Theta

b) Iota

c) Pi

d) Chi

View Answer

Explanation: Pi and Rho are permutation operations.

6. In SHA-3, for a message digest size of 256, what is the bitrate ‘r’ (capacity = 512) ?

a) 576

b) 1088

c) 1152

d) 832

View Answer

Explanation: In SHA-3, c+r = 1600, therefore here ‘r’ = 1088.

7. The sponge construction involves 2 phases, these are

a) absorbing and adaptive

b) adaptive and squeezing

c) absorbing and squeezing

d) none of the mentioned

View Answer

Explanation: The sponge construction involves 2 phases – the absorbing phase and the squeezing phase.

8. Within the Keccak function-f, the 1600 bits are arranged into a 5 x 5 x 64 array a. The 64-bit units are referred to as

a) lemma

b) z co-ordinate

c) kernel

d) lanes

View Answer

Explanation: They are referred to as lanes.

9. What are the co-ordinates of the bottom-right most lane?

a) L[4 ,4].

b) L[4, 0].

c) L[5, 5].

d) L[5, 1].

View Answer

Explanation: The bottom right most lane corresponds to x=4 and y=0 i.e. L[4, 0].

10. How many iterations / rounds does the Keccak function have ?

a) 12

b) 36

c) 16

d) 24

View Answer

Explanation: The Keccak function has 24 rounds, each of which has 5 step functions.

11. Which step function works only W[0, 0]?

a) Theta

b) Iota

c) Pi

d) Chi

View Answer

Explanation: The last step function Iota works only on W[0, 0].

12. SHA-3 has an advantage over other algorithms because, there is no need for table look ups, arithmetic operations or data dependent operations.

a) True

b) False

View Answer

Explanation: The statement is true. SHA-3 does not require look-up tables, and is thus easily implemented on both hardware and software.

**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__.