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web.groovymark@gmail.com
- November 28, 2024
Question 41
Which of the following describes a chosen-plaintext attack?
a) The attacker encrypts chosen plaintext and compares it with the ciphertext
b) The attacker chooses specific ciphertext to decrypt and analyze
c) The attacker intercepts communications and attempts to decrypt them
d) The attacker uses brute-force attempts to guess the encryption key
Correct Answer: a) The attacker encrypts chosen plaintext and compares it with the ciphertext
Explanation: In a chosen-plaintext attack, the attacker chooses plaintext to encrypt and then compares it to the resulting ciphertext to gather information about the encryption algorithm.
Question 42
Which encryption algorithm is commonly used for securing email communications using digital signatures?
a) AES
b) RSA
c) Blowfish
d) ChaCha20
Correct Answer: b) RSA
Explanation: RSA is commonly used to secure email communications with digital signatures, providing both authentication and message integrity.
Question 43
What is the main advantage of stream ciphers over block ciphers?
a) Stream ciphers are more secure than block ciphers
b) Stream ciphers are faster and better suited for real-time data transmission
c) Stream ciphers use smaller keys than block ciphers
d) Stream ciphers can encrypt larger blocks of data at once
Correct Answer: b) Stream ciphers are faster and better suited for real-time data transmission
Explanation: Stream ciphers encrypt data one bit or byte at a time, making them faster and better suited for real-time applications like audio and video streaming.
Question 44
Which of the following describes a rainbow table attack?
a) An attack that uses frequency analysis to determine the key
b) An attack that precomputes possible hash values to crack passwords
c) An attack that intercepts encrypted data to decrypt it
d) An attack that reuses previously captured data to gain access
Correct Answer: b) An attack that precomputes possible hash values to crack passwords
Explanation: A rainbow table attack uses a precomputed table of hash values and their corresponding plaintexts to quickly crack hashed passwords.
Question 45
Which of the following encryption algorithms is a symmetric block cipher?
a) AES
b) RSA
c) ECC
d) DSA
Correct Answer: a) AES
Explanation: AES is a symmetric block cipher that encrypts data in fixed-size blocks using the same key for both encryption and decryption.
Question 46
What is the primary characteristic of a block cipher?
a) It encrypts data one bit at a time
b) It encrypts data in fixed-size blocks
c) It uses only public keys for encryption
d) It is always slower than stream ciphers
Correct Answer: b) It encrypts data in fixed-size blocks
Explanation: A block cipher encrypts data in fixed-size blocks, typically 64 or 128 bits, as opposed to stream ciphers that encrypt data one bit or byte at a time.
Question 47
Which type of attack aims to discover patterns between ciphertext and plaintext pairs?
a) Differential cryptanalysis
b) Chosen ciphertext attack
c) Timing attack
d) Replay attack
Correct Answer: a) Differential cryptanalysis
Explanation: Differential cryptanalysis involves analyzing differences between plaintext and ciphertext pairs to discover patterns that can be used to break the encryption.
Question 48
What is the key length of the AES-256 encryption algorithm?
a) 128 bits
b) 192 bits
c) 256 bits
d) 512 bits
Correct Answer: c) 256 bits
Explanation: AES-256 uses a key length of 256 bits, providing a high level of security for encrypted communications and data storage.
Question 49
Which of the following best describes a certificate revocation list (CRL)?
a) A list of certificates that have been revoked by the issuing Certificate Authority
b) A list of public keys for verifying digital signatures
c) A method for validating a digital certificate’s authenticity
d) A protocol for encrypting certificates during transmission
Correct Answer: a) A list of certificates that have been revoked by the issuing Certificate Authority
Explanation: A CRL is a list of certificates that have been revoked before their expiration date, allowing users and systems to check whether a certificate is still valid
Question 50
Which of the following describes a timing attack?
a) An attack that measures the time taken to perform cryptographic operations
b) An attack that intercepts encrypted communications to decrypt them
c) An attack that reuses previously captured data to gain access
d) An attack that precomputes possible hash values to crack passwords
Correct Answer: a) An attack that measures the time taken to perform cryptographic operations
Explanation: A timing attack exploits the time taken to perform cryptographic operations, potentially allowing attackers to deduce the encryption key or plaintext.
