D334 Introduction to Cryptography - Set 2 - Part 2

Correct Answer: To add random data to the password before hashing

Salting involves adding random data to a password before hashing it, which prevents attackers from using precomputed rainbow tables to crack hashed passwords.

Correct Answer: All of the above

IPsec, TLS, and SSL all use symmetric encryption to establish secure communication tunnels, with the session key typically negotiated through asymmetric encryption.

Correct Answer: 128 bits

AES uses a block size of 128 bits, regardless of the key length, which can be 128, 192, or 256 bits.

Correct Answer: RSA

RSA is widely used for securing digital signatures because it is an asymmetric encryption algorithm that provides strong authentication and integrity.

Correct Answer: To generate and store cryptographic keys securely

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.

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

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.

Correct Answer: Elliptic Curve Cryptography

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.

Correct Answer: It produces a fixed-length output

A hash function takes an input of any length and produces a fixed-length output, typically used for data integrity and authentication.

Correct Answer: The attacker selects ciphertext to be decrypted and obtains the corresponding plaintext

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.

Correct Answer: CTR

CTR mode allows for parallel processing because each block is encrypted independently of the others, improving performance in systems where speed is critical.

Correct Answer: AES

AES uses a substitution-permutation network, which involves multiple rounds of substitutions and permutations to encrypt data securely.

Correct Answer: Key exhaustion attack

A key exhaustion attack involves systematically trying all possible keys to discover the correct one, often exploiting weaknesses in the key generation process.

Correct Answer: It offers equivalent security with smaller key sizes

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.

Correct Answer: RSA

RSA relies on the difficulty of factorizing the product of two large prime numbers, making it secure for encryption and digital signatures.

Correct Answer: To verify the identity of the sender and ensure data integrity

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.

Correct Answer: Diffie-Hellman

Diffie-Hellman is a widely used key exchange protocol in asymmetric cryptography, allowing two parties to securely exchange keys over an insecure channel.

Correct Answer: It encrypts identical plaintext blocks into identical ciphertext blocks

ECB mode is vulnerable because it encrypts identical plaintext blocks into identical ciphertext blocks, making it susceptible to pattern analysis and other attacks.

Correct Answer: SPECK

SPECK is a lightweight symmetric block cipher optimized for software implementation, supporting variable key sizes for different use cases.

Correct Answer: Integrity

Integrity ensures that a message has not been tampered with during transmission, typically verified using a hash or digital signature.

Correct Answer: Substitution cipher

A substitution cipher replaces each letter in the plaintext with another letter while maintaining the order of the letters.