-
web.groovymark@gmail.com
- November 28, 2024
Question 41
What type of attack exploits the fact that two different inputs can produce the same hash value?
a) Replay attack
b) Collision attack
c) Man-in-the-middle attack
d) Brute-force attack
Correct Answer: b) Collision attack
Explanation: A collision attack exploits the fact that two different inputs can produce the same hash value, undermining the integrity of the hash function and potentially leading to forged digital signatures.
Question 42
Which of the following algorithms is a stream cipher?
a) AES
b) RSA
c) RC4
d) Blowfish
Correct Answer: c) RC4
Explanation: RC4 is a stream cipher that encrypts data one bit or byte at a time, commonly used in older encryption protocols like WEP and WPA.
Question 43
Which of the following is a weakness of the WPA encryption protocol?
a) It uses a fixed initialization vector
b) It is vulnerable to replay attacks
c) It uses RC4, which is insecure
d) It uses 128-bit AES encryption
Correct Answer: c) It uses RC4, which is insecure
Explanation: WPA uses the RC4 stream cipher, which has known vulnerabilities, making it less secure compared to modern encryption methods like AES used in WPA2.
Question 44
Which of the following cryptographic algorithms is commonly used for key exchange?
a) AES
b) RSA
c) Diffie-Hellman
d) Blowfish
Correct Answer: c) Diffie-Hellman
Explanation: Diffie-Hellman is widely used for secure key exchange between two parties, allowing them to establish a shared secret key over an unsecured communication channel.
Question 45
Which block cipher mode is considered the weakest due to its lack of an initialization vector (IV)?
a) Cipher Block Chaining (CBC)
b) Electronic Code Book (ECB)
c) Counter Mode (CTR)
d) Output Feedback (OFB)
Correct Answer: b) Electronic Code Book (ECB)
Explanation: ECB mode is considered weak because it does not use an IV, which results in identical plaintext blocks being encrypted into identical ciphertext blocks, making it vulnerable to pattern analysis.
Question 46
Which of the following describes the main advantage of elliptic curve cryptography (ECC)?
a) ECC uses larger keys, making it more secure than RSA
b) ECC provides the same security as RSA with smaller key sizes
c) ECC is easier to implement than other public key cryptosystems
d) ECC provides perfect forward secrecy by default
Correct Answer: b) ECC provides the same security as RSA with smaller key sizes
Explanation: ECC offers equivalent security to RSA but with much smaller key sizes, making it more efficient in terms of computation and storage, especially for mobile and embedded devices.
Question 47
Which of the following describes a chosen-ciphertext attack?
a) The attacker selects arbitrary plaintext and observes the corresponding ciphertext
b) The attacker intercepts and decrypts a specific ciphertext
c) The attacker alters ciphertext to cause predictable errors in decryption
d) The attacker chooses a ciphertext and obtains its corresponding decrypted plaintext
Correct Answer: d) The attacker chooses a ciphertext and obtains its corresponding decrypted plaintext
Explanation: In a chosen-ciphertext attack, the attacker selects a ciphertext and obtains its decrypted plaintext, often using this information to deduce the encryption key or break the cryptosystem.
Question 48
What is a primary risk of using a non-synchronizing cipher mode, such as Cipher Feedback (CFB)?
a) It is more vulnerable to brute-force attacks
b) If a block of ciphertext is lost, subsequent blocks cannot be decrypted
c) It requires longer keys than other modes
d) It does not provide authentication
Correct Answer: b) If a block of ciphertext is lost, subsequent blocks cannot be decrypted
Explanation: In a non-synchronizing cipher mode like CFB, each ciphertext block depends on the previous one. If a block is lost or corrupted, the subsequent blocks cannot be decrypted correctly.
Question 49
Which of the following is used to verify the identity of a server in an HTTPS connection?
a) Symmetric key
b) Private key
c) Digital certificate
d) Public key
Correct Answer: c) Digital certificate
Explanation: A digital certificate is used to verify the identity of a server in an HTTPS connection, ensuring that the server is legitimate and has the correct public key for encryption.
Question 50
What is the primary function of a Trusted Platform Module (TPM) in cryptography?
a) To generate public/private key pairs
b) To encrypt full disk volumes
c) To provide hardware-level encryption and secure key storage
d) To store digital certificates
Correct Answer: c) To provide hardware-level encryption and secure key storage
Explanation: A TPM is a dedicated hardware component that provides hardware-level encryption, securely stores cryptographic keys, and enhances system security.
