Operating System Multiple Choice Questions on “Security – Cryptography”.
1. What is the preferred way of encryption?
a) pre shared secret key
b) using key distribution center (KDC)
c) public key-encryption
d) symmetric key
Answer: c
Clarification: Pre Shared key can be compromised and either party can be suspected. Likewise KDC or symmetric key can have breach which are undesirable. Public and private key encryption is a known industry standard.
2. What is not a role of encryption?
a) It is used to protect data from unauthorized access during transmission
b) It is used to ensure user authentication
c) It is used to ensure data integrity
d) It is used to ensure data corruption doesn’t happens
Answer: d
Clarification: Encryption doesn’t have error correction or detection facility thus cannot be used to safeguard from data corruption.
3. What is cipher-block chaining?
a) Data is logically ‘ANDed’ with previous block
b) Data is logically ‘ORed’ with previous block
c) Data is logically ‘XORed’ with previous block
d) None of the mentioned
Answer: c
Clarification: None.
4. What is not an encryption standard?
a) AES
b) TES
c) Triple DES
d) DES
Answer: b
Clarification: None.
5. Which of the following is not a stream cipher?
a) Two fish
b) RC5
c) RC4
d) TBONE
Answer: d
Clarification: None.
6. What is a Hash Function?
a) It creates a small flexible block of data
b) It creates a small,fixed block of data
c) It creates a encrypted block of data
d) None of the mentioned
Answer: b
Clarification: None.
7. MD5 produces __________ bits hash data.
a) 128
b) 150
c) 160
d) 112
Answer: a
Clarification: None.
8. SHA-1 produces __________ bit of hash.
a) 128
b) 160
c) 150
d) 112
Answer: b
Clarification: None.
9. Which two of the following are authentication algorithms?
a) MAC
b) AES
c) DAS
d) Digital-signature
Answer: a
Clarification: None.
10. What is the role of Key Distribution Center?
a) It is used to distribute keys to everyone in world
b) It intended to reduce the risks inherent in exchanging keys
c) All of the mentioned
d) None of the mentioned
Answer: b