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web.groovymark@gmail.com
- November 29, 2024
Question 01
What is the primary function of AES (Advanced Encryption Standard)?
a) Key exchange
b) Symmetric encryption
c) Asymmetric encryption
d) Digital signature
Correct Answer: b) Symmetric encryption
Explanation: AES is a symmetric encryption algorithm that encrypts data using the same key for both encryption and decryption.
Question 02
Which encryption algorithm is commonly used for securing web traffic via HTTPS?
a) RSA
b) AES
c) DES
d) ECC
Correct Answer: a) RSA
Explanation: RSA is commonly used in HTTPS for securing web traffic, as it provides strong encryption for key exchanges and digital signatures.
Question 03
Which of the following describes the primary weakness of DES?
a) It uses a small key size
b) It is difficult to implement
c) It is a public-key encryption algorithm
d) It cannot be used in block cipher mode
Correct Answer: a) It uses a small key size
Explanation: DES has a small key size of 56 bits, which makes it vulnerable to brute-force attacks.
Question 04
What does the term ‘collision’ refer to in cryptography?
a) Two different ciphertexts produce the same plaintext
b) Two different inputs produce the same hash value
c) A public key is used for decryption
d) The same message is encrypted multiple times
Correct Answer: b) Two different inputs produce the same hash value
Explanation: A collision occurs when two different inputs produce the same hash value, compromising the security of the hash function.
Question 05
Which of the following is a major advantage of using elliptic curve cryptography (ECC) over RSA?
a) ECC provides stronger encryption with smaller key sizes
b) ECC is faster than RSA for large key sizes
c) ECC is easier to implement than RSA
d) ECC uses symmetric encryption
Correct Answer: a) ECC provides stronger encryption with smaller key sizes
Explanation: ECC offers equivalent security to RSA with much smaller key sizes, making it more efficient for encryption and key exchange.
Question 06
Which of the following is the primary purpose of a digital certificate?
a) To store private keys securely
b) To establish the identity of a sender or receiver
c) To encrypt data during transmission
d) To generate random numbers for encryption
Correct Answer: b) To establish the identity of a sender or receiver
Explanation: Digital certificates are used to verify the identity of the sender or receiver in a communication, ensuring that public keys belong to the intended party.
Question 07
Which algorithm is primarily used for generating digital signatures?
a) DES
b) AES
c) RSA
d) RC4
Correct Answer: c) RSA
Explanation: RSA is commonly used for generating digital signatures, which provide authentication and ensure the integrity of a message.
Question 08
Which of the following best describes the purpose of a block cipher mode of operation?
a) To break data into smaller units for encryption
b) To define how encryption and decryption are performed on data blocks
c) To enhance the security of stream ciphers
d) To enable key exchange between parties
Correct Answer: b) To define how encryption and decryption are performed on data blocks
Explanation: Block cipher modes of operation define how data blocks are encrypted and decrypted using a block cipher algorithm like AES or DES.
Question 09
Which type of attack attempts to decrypt ciphertext by trying all possible keys?
a) Known plaintext attack
b) Brute-force attack
c) Replay attack
d) Man-in-the-middle attack
Correct Answer: b) Brute-force attack
Explanation: In a brute-force attack, the attacker tries every possible key until the correct one is found to decrypt the ciphertext.
Question 10
What is the primary advantage of using a symmetric encryption algorithm like AES?
a) It allows for faster encryption and decryption
b) It provides stronger encryption than asymmetric algorithms
c) It requires no key exchange
d) It is easier to implement than asymmetric encryption
Correct Answer: a) It allows for faster encryption and decryption
Explanation: Symmetric encryption algorithms like AES are generally faster than asymmetric algorithms because they use the same key for both encryption and decryption.
Question 11
Which cryptographic algorithm is based on the difficulty of factorizing large prime numbers?
a) AES
b) RSA
c) DES
d) SHA-256
Correct Answer: b) RSA
Explanation: RSA relies on the mathematical difficulty of factorizing large prime numbers, which is the basis for its security.
Question 12
What is the purpose of hashing in cryptography?
a) To encrypt sensitive data
b) To ensure data integrity
c) To generate a private key
d) To exchange encryption keys
Correct Answer: b) To ensure data integrity
Explanation: Hashing is used to ensure data integrity by producing a fixed-length hash value from input data, allowing verification that the data has not been altered.
Question 13
Which cryptographic concept ensures that a communication session is secure, even if long-term keys are compromised?
a) Forward secrecy
b) Hashing
c) Digital signatures
d) Symmetric encryption
Correct Answer: a) Forward secrecy
Explanation: Forward secrecy ensures that if long-term keys are compromised, past communication sessions remain secure because session keys are not derived from long-term keys.
Question 14
Which of the following best describes a stream cipher?
a) It encrypts data one bit at a time
b) It encrypts data in fixed-size blocks
c) It always uses an initialization vector
d) It requires a public and private key pair
Correct Answer: a) It encrypts data one bit at a time
Explanation: Stream ciphers encrypt data one bit at a time, making them faster for real-time applications compared to block ciphers.
Question 15
Which of the following algorithms is a public key encryption method?
a) AES
b) DES
c) RSA
d) RC5
Correct Answer: c) RSA
Explanation: RSA is a public key encryption algorithm, while AES, DES, and RC5 are symmetric encryption algorithms.
Question 16
What is the primary function of salting in cryptographic hashing?
a) To enhance the security of the hash by adding random data
b) To compress the input data into a fixed length
c) To reduce the size of the hash output
d) To encrypt the data before hashing
Correct Answer: a) To enhance the security of the hash by adding random data
Explanation: Salting adds random data to the input before hashing, preventing attackers from using precomputed rainbow tables to crack the hash.
Question 17
What is the block size of the AES encryption algorithm?
a) 64 bits
b) 128 bits
c) 192 bits
d) 256 bits
Correct Answer: b) 128 bits
Explanation: AES has a fixed block size of 128 bits, regardless of the key length used in the encryption process.
Question 18
Which of the following describes a chosen-ciphertext attack?
a) The attacker chooses plaintext to encrypt and observe the ciphertext
b) The attacker selects ciphertext to decrypt and obtain the corresponding plaintext
c) The attacker intercepts and alters ciphertext in transit
d) The attacker uses frequency analysis to break the cipher
Correct Answer: b) The attacker selects ciphertext to decrypt and obtain the corresponding plaintext
Explanation: In a chosen-ciphertext attack, the attacker selects specific ciphertext to be decrypted, using the resulting plaintext to analyze the encryption method.
Question 19
Which of the following is a symmetric encryption algorithm?
a) RSA
b) AES
c) ECC
d) Diffie-Hellman
Correct Answer: b) AES
Explanation: AES is a symmetric encryption algorithm, meaning the same key is used for both encryption and decryption.
Question 20
Which of the following is a key exchange protocol used in asymmetric encryption?
a) RSA
b) AES
c) Diffie-Hellman
d) SHA-256
Correct Answer: c) Diffie-Hellman
Explanation: Diffie-Hellman is a key exchange protocol used in asymmetric encryption to establish a shared secret between two parties over an insecure channel.
