1. Blowfish encrypts blocks of plaintext which have size
a) 256 bits
b) 64 bits
c) 72 bits
d) 128 bits
Explanation: The size of the blocks of the plaintext is 64 bits each.
2. The blowfish algorithm can be implemented on 16 bit processors.
a) True
b) False
Explanation: The statement is false as 32/64 bit processors are only capable of encrypting/decrypting the blowfish algorithm.
3. What is the minimum size of the key in blowfish algorithm?
a) 64 bits
b) 32 bits
c) 56 bits
d) 48 bits
Explanation: The minimum size of the key in blowfish algorithm is 4 bytes or 32 bits.
4. The blowfish algorithm’s key expansion converts a key of at most 448 bits into several subkey arrays totaling ___________ bytes.
a) 4096
b) 4608
c) 4168
d) 4864
Explanation: Key expansion converts a key of at most 448 bits into several sub key arrays totaling 4168 bytes i.e. eighteen 32-bit sub keys + four 8×32-bit s boxes = 4168.
5. Blowfish algorithm uses the Feistel Structure.
a) True
b) False
Explanation: In the blowfish algorithm data encryption occurs via a 16-round Feistel network.
6. XOR and addition operations take place on bytes of size
a) 8 bits
b) 16 bits
c) 32 bits
d) 64 bits
Explanation: XOR and addition operations take place on bytes of size 32 bits.
7. How many S-boxes are present in the blowfish algorithm?
a) 2
b) 4
c) 6
d) 8
Explanation: There are 4 s-boxes in the blowfish algorithm.
8. How many entries are present in each of the S-boxes present in the blowfish algorithm?
a) 256
b) 512
c) 1024
d) 64
Explanation: There are 4 s-boxes with 256 entries each in the blowfish algorithm.
9. How many 3DES blocks are present in the ANSI X9.17 PRNG?
a) 2
b) 3
c) 4
d) 5
Explanation: There are 3 3DES blocks in the ANSI X9.17 PRNG.
10. The Generate function precedes the Update phase in CTR_DRBG.
a) True
b) False
Explanation: The Generate function comes after the Update Phase function.