1. Which among the following cannot be used in the case of stream ciphers?

a) TRNGs

b) PRNGs

c) PRFs

d) All of the mentioned

### View Answer

2. A stream cipher key is usually of size ___ or 128 bits.

a) 56

b) 64

c) 54

d) 48

### View Answer

3. Which among the following has the lowest bitrate ?

a) PRF

b) TRNG

c) PRNG

d) All have the same bitrate

### View Answer

4. RC4 was built on the sole purpose of generating random bits i.e. to act as a PRNG.

a) True

b) False

### View Answer

5. Maurer’s Universal Statistical Test is –

a) a test to determine whether the number of runs of ones and zeros of various lengths is as expected

b) a test to detect if a sequence can be significantly compressed without loss of information

c) a test to determine whether the number of ones and zeros in a sequence is approx the same as in a truely random o/p

d) a test for the check of evenness in the 1s and 0s

### View Answer

6. Runs Test is

a) a test to determine whether the number of runs of ones and zeros of various lengths is as expected

b) a test to detect if a sequence can be significantly compressed without loss of information

c) a test to determine whether the number of ones and zeros in a sequence is approx the same as in a truely random o/p

d) a test for the check of evenness in the 1s and 0s

### View Answer

7. Frequency Test is

a) a test to determine whether the number of runs of ones and zeros of various lengths is as expected

b) a test to detect if a sequence can be significantly compressed without loss of information

c) a test for the check of evenness in the 1s and 0s

d) a test to determine whether the number of ones and zeros in a sequence is approx the same as in a truely random o/p

### View Answer

8. We should not be able to determine the seed from any previous knowledge of the bits sequence. This is the property of backward unpredictability.

a) True

b) False

### View Answer

9. Forward Unpredictability is a property when the seed is unknown, and the next output bit is the sequence should be unpredictable.

a) True

b) False