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WorksheetsQUIZ
Total questions: 25
Worksheet time: 4mins
1. What is asymmetric cryptography?
A system that uses a single secret key for both encryption and decryption
A system that uses two different but related keys — one public and one private
A method that hides data using substitution and transposition
A type of steganography used to conceal messages
2. What are the two types of keys used in asymmetric encryption?
Secret key and Session key
Encryption key and Hash key
Public key and Private key
Sender key and Receiver key
3. Which key is kept secret in asymmetric cryptography?
Public key
Private key
Encryption key
Hash key
4. Which key is shared publicly in asymmetric cryptography?
Private key
Symmetric key
Public key
Master key
5. Why is asymmetric cryptography also known as public-key cryptography?
Because it hides data using complex algorithms
Because one key is made public for encryption and verification
Because both keys are secret
Because it is faster than symmetric cryptography
6.What is the main purpose of the RSA algorithm?
To compress data
To encrypt and decrypt data using public and private keys
To generate random numbers
To check data integrity
7. In RSA, what are ‘p’ and ‘q’?
Plaintext and ciphertext
Two random prime numbers
Public and private keys
Encryption and decryption exponents
8. Which of the following represents the public key in RSA?
(e, d)
(n, e)
(n, d)
(p, q)
9. In RSA, the special number that is used for encrypting messages along with the modulus is called the (a) key.
10. The mathematical function used to calculate in RSA is called the Euler’s (a) function.
11. What is the main purpose of key distribution and management in secure communications?
To encrypt only public data
To manage security mechanisms by distributing and maintaining cryptographic keys
To replace authentication protocols
To avoid encryption
12. Which of the following is an example of a key agreement protocol?
RSA
Diffie–Hellman key exchange
AES
DES
13. The Internet Key Exchange (IKE) protocol is mainly used for setting up secure associations in which framework?
SSL
IPSec
TLS
SSH
14. In the SPINS security architecture for sensor networks, each sensor node shares a secret key with which entity?
Neighboring sensors
Base station
Key Distribution Center (KDC)
Random sensor group
15. What type of cryptographic technique does SPINS avoid using?
Asymmetric (public-key) cryptography
Stream ciphers
Hash functions
Symmetric cryptography
16. What does “forward secrecy” ensure in secure group communication?
Keys are never updated
Messages are stored permanently
Former members cannot access current communications
New members can read old messages
17. What does “backward secrecy” mean in the context of group communication?
Former members can access old data
New members cannot access previous communications
Group members share passwords
Only symmetric encryption is used
18. In group-key distribution, what is the main difference between broadcast encryption and multicast key distribution?
One uses private keys; the other uses public keys
They are identical methods
Broadcast encryption requires a KDC; multicast doesn’t
Broadcast encryption uses stateless receivers, multicast uses stateful receivers
19. In a centralized approach to multicast key distribution, which entity is responsible for key management?
Every group member
Network router
Key Distribution Center (KDC)
Sensor base station
20. Which of the following protocols are examples of key distribution protocols that optimize message exchange between a KDC and group members?
Diffie–Hellman and RSA
LKH and MARKS
SPINS and DTLS
AES and DES
21. Which hash functions use a sponge construction to absorb and squeeze data?
PHOTON and SPONGENT
MD5 and SHA-1
H-PRESENT and DM-PRESENT
None of the above
22. Which hash function was selected by NIST as the winner of the SHA-3 competition?
PHOTON
QUARK
Keccak
SPONGENT
23. Why do we need lightweight cryptographic hash functions?
To make hash outputs longer
To run on devices with limited power and memory
To replace passwords
To make encryption faster
24. The hash functions DM-PRESENT and H-PRESENT are based on which block cipher?
PRESENT
AES
DES
Blowfish
25. Most modern lightweight hash functions like PHOTON, QUARK, and SPONGENT are built using which construction method?
Feistel Network
Sponge Construction
Substitution-Permutation Network
Merkle–Damgård Construction
