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web.groovymark@gmail.com
- November 28, 2024
Question 21
What is the primary function of salting in password hashing?
a) To increase the key size used in encryption
b) To add random data to the password before hashing
c) To replace hashing algorithms with encryption
d) To ensure that the hash function produces the same output each time
Correct Answer: b) To add random data to the password before hashing
Explanation: Salting involves adding random data to a password before hashing it, which prevents attackers from using precomputed rainbow tables to crack hashed passwords.
Question 22
Which of the following protocols is used to establish a secure communication tunnel using symmetric encryption?
a) IPsec
b) TLS
c) SSL
d) All of the above
Correct Answer: d) All of the above
Explanation: IPsec, TLS, and SSL all use symmetric encryption to establish secure communication tunnels, with the session key typically negotiated through asymmetric encryption.
Question 23
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 uses a block size of 128 bits, regardless of the key length, which can be 128, 192, or 256 bits.
Question 24
Which encryption algorithm is primarily used for securing digital signatures?
a) AES
b) DES
c) RSA
d) RC4
Correct Answer: c) RSA
Explanation: RSA is widely used for securing digital signatures because it is an asymmetric encryption algorithm that provides strong authentication and integrity.
Question 25
What is the role of a Trusted Platform Module (TPM) in cryptographic systems?
a) To store digital certificates
b) To generate and store cryptographic keys securely
c) To perform hashing operations
d) To encrypt individual files on the system
Correct Answer: b) To generate and store cryptographic keys securely
Explanation: A TPM is a hardware component that provides secure storage and generation of cryptographic keys, enhancing system security by preventing unauthorized access to these keys.
Question 26
Which of the following best describes a man-in-the-middle (MITM) attack?
a) The attacker encrypts communications between two parties
b) The attacker intercepts and alters communications between two parties
c) The attacker uses brute-force techniques to crack encrypted communications
d) The attacker generates random keys to encrypt intercepted data
Correct Answer: b) The attacker intercepts and alters communications between two parties
Explanation: In a man-in-the-middle attack, the attacker intercepts communications between two parties and may alter or eavesdrop on the conversation without their knowledge.
Question 27
Which encryption technique is commonly used in blockchain technologies?
a) AES
b) RSA
c) Elliptic Curve Cryptography (ECC)
d) DES
Correct Answer: c) Elliptic Curve Cryptography (ECC)
Explanation: ECC is commonly used in blockchain technologies like Bitcoin due to its efficiency and smaller key sizes, providing strong encryption for digital signatures and key exchange.
Question 28
Which of the following is a characteristic of a hash function?
a) It is reversible
b) It produces a fixed-length output
c) It uses a private key
d) It requires padding for encryption
Correct Answer: b) It produces a fixed-length output
Explanation: A hash function takes an input of any length and produces a fixed-length output, typically used for data integrity and authentication.
Question 29
Which of the following describes a chosen-ciphertext attack?
a) The attacker intercepts encrypted data and attempts to decrypt it without knowing the key
b) The attacker selects ciphertext to be decrypted and obtains the corresponding plaintext
c) The attacker performs brute-force attempts to decrypt ciphertext
d) The attacker uses frequency analysis to determine the encryption key
Correct Answer: b) The attacker selects ciphertext to be decrypted and obtains the corresponding plaintext
Explanation: In a chosen-ciphertext attack, the attacker chooses specific ciphertext to be decrypted and uses the resulting plaintext to gather information about the encryption key.
Question 30
Which of the following block cipher modes allows for independent encryption of blocks, facilitating parallel processing?
a) ECB
b) CBC
c) CTR
d) OFB
Correct Answer: c) CTR
Explanation: CTR mode allows for parallel processing because each block is encrypted independently of the others, improving performance in systems where speed is critical.
Question 31
Which encryption technique uses a substitution-permutation network?
a) RSA
b) AES
c) DES
d) Blowfish
Correct Answer: b) AES
Explanation: AES uses a substitution-permutation network, which involves multiple rounds of substitutions and permutations to encrypt data securely.
Question 32
Which of the following types of attacks is specifically aimed at discovering weaknesses in the key generation process of encryption algorithms?
a) Known plaintext attack
b) Key exhaustion attack
c) Key exchange attack
d) Timing attack
Correct Answer: b) Key exhaustion attack
Explanation: A key exhaustion attack involves systematically trying all possible keys to discover the correct one, often exploiting weaknesses in the key generation process.
Question 33
What is the primary benefit of using elliptic curve cryptography (ECC) over traditional methods like RSA?
a) It provides more secure digital certificates
b) It requires larger key sizes for greater security
c) It offers equivalent security with smaller key sizes
d) It is more commonly supported by legacy systems
Correct Answer: c) It offers equivalent security with smaller key sizes
Explanation: ECC provides the same level of security as RSA but with much smaller key sizes, making it more efficient in terms of computation and storage.
Question 34
Which encryption algorithm is based on the difficulty of factorizing the product of two large prime numbers?
a) AES
b) DES
c) RSA
d) ECC
Correct Answer: c) RSA
Explanation: RSA relies on the difficulty of factorizing the product of two large prime numbers, making it secure for encryption and digital signatures.
Question 35
What is the purpose of a digital signature in cryptography?
a) To encrypt data for secure transmission
b) To verify the identity of the sender and ensure data integrity
c) To establish a secure communication channel
d) To generate cryptographic keys
Correct Answer: b) To verify the identity of the sender and ensure data integrity
Explanation: A digital signature is used to verify the authenticity and integrity of a message by ensuring it was sent by the claimed sender and has not been tampered with.
Question 36
Which of the following protocols is used for secure key exchange in asymmetric cryptography?
a) AES
b) RSA
c) Diffie-Hellman
d) DES
Correct Answer: c) Diffie-Hellman
Explanation: Diffie-Hellman is a widely used key exchange protocol in asymmetric cryptography, allowing two parties to securely exchange keys over an insecure channel.
Question 37
What is the primary weakness of using the Electronic Code Book (ECB) encryption mode?
a) It requires too much computational power
b) It encrypts identical plaintext blocks into identical ciphertext blocks
c) It does not support parallel processing
d) It is only suitable for small amounts of data
Correct Answer: b) It encrypts identical plaintext blocks into identical ciphertext blocks
Explanation: ECB mode is vulnerable because it encrypts identical plaintext blocks into identical ciphertext blocks, making it susceptible to pattern analysis and other attacks.
Question 38
Which of the following is a symmetric block cipher that supports variable key sizes and is optimized for software implementation?
a) AES
b) RSA
c) SPECK
d) Blowfish
Correct Answer: c) SPECK
Explanation: SPECK is a lightweight symmetric block cipher optimized for software implementation, supporting variable key sizes for different use cases.
Question 39
Which cryptographic concept ensures that a message cannot be modified without detection?
a) Confidentiality
b) Non-repudiation
c) Integrity
d) Authenticity
Correct Answer: c) Integrity
Explanation: Integrity ensures that a message has not been tampered with during transmission, typically verified using a hash or digital signature.
Question 40
Which type of cipher involves replacing each letter in the plaintext with another letter, but keeping the order of the letters unchanged?
a) Transposition cipher
b) Stream cipher
c) Substitution cipher
d) Block cipher
Correct Answer: c) Substitution cipher
Explanation: A substitution cipher replaces each letter in the plaintext with another letter while maintaining the order of the letters.
