D334 Introduction to Cryptography - Set 5 - Part 2

Correct Answer: Replay attack

A replay attack involves capturing valid data transmissions and reusing them at a later time to gain unauthorized access or perform malicious actions.

Correct Answer: 256 bits

AES-256 uses a 256-bit key for encryption, providing a high level of security.

Correct Answer: To make the password hash harder to crack by adding random data

Salting adds random data to the password before hashing, making it more difficult for attackers to use precomputed rainbow tables to crack the hash.

Correct Answer: RSA

RSA is commonly used for generating digital signatures, providing authentication and data integrity by allowing the recipient to verify the sender's identity.

Correct Answer: It issues and manages digital certificates for public key infrastructure

A Certificate Authority (CA) is responsible for issuing and managing digital certificates used in public key infrastructure (PKI).

Correct Answer: An attacker intercepts and alters communications between two parties

A man-in-the-middle attack occurs when an attacker intercepts communications between two parties and potentially alters the data without their knowledge.

Correct Answer: To ensure that identical plaintexts produce different ciphertexts

A nonce is a random value used only once in encryption to ensure that the same plaintext encrypted multiple times results in different ciphertexts.

Correct Answer: AES

AES is a symmetric block cipher that encrypts data in fixed-size blocks using the same key for both encryption and decryption.

Correct Answer: SHA-256

SHA-256 is a cryptographic hash algorithm that generates a fixed-length hash value, ensuring data integrity.

Correct Answer: Side-channel attack

In a side-channel attack, the attacker analyzes the time, power consumption, or other physical characteristics of encryption operations to gather information about the encryption key.

Correct Answer: They generate a fixed-length output from a variable-length input

Hashing algorithms generate a fixed-length output, called a hash value, from a variable-length input and are used to ensure data integrity.

Correct Answer: Man-in-the-middle attack

In a man-in-the-middle attack, the attacker intercepts and potentially modifies encrypted messages in transit, altering the data without the sender or receiver's knowledge.

Correct Answer: CTR

Counter (CTR) mode allows for parallel processing of blocks because each block is encrypted independently, improving performance in high-speed environments.

Correct Answer: Asymmetric encryption

Asymmetric encryption uses a public key for encryption and a private key for decryption, making it more secure for key exchange.

Correct Answer: To ensure data integrity by generating a fixed-length output

A cryptographic hash function ensures data integrity by generating a unique, fixed-length hash value from input data, allowing verification that the data has not been altered.

Correct Answer: To verify the identity of the certificate holder and provide public key information

Digital certificates in PKI are used to verify the identity of the certificate holder and provide the corresponding public key for secure communications.

Correct Answer: RSA

RSA is commonly used for generating digital signatures, providing authentication and data integrity by allowing the recipient to verify the sender's identity.

Correct Answer: Chosen-ciphertext attack

In a chosen-ciphertext attack, the attacker selects ciphertext to be decrypted and analyzes the resulting plaintext to gather information about the encryption key.

Correct Answer: To ensure that the same password generates different hash values

Salting adds random data to passwords before hashing to ensure that identical passwords result in different hash values, making it harder to crack.

Correct Answer: ECC

Elliptic Curve Cryptography (ECC) is based on the mathematical difficulty of solving discrete logarithms, making it secure for encryption and key exchange.