D334 Introduction to Cryptography - Set 3 - Part 1

Correct Answer: Symmetric encryption

AES is a symmetric encryption algorithm that encrypts data using the same key for both encryption and decryption.

Correct Answer: RSA

RSA is commonly used in HTTPS for securing web traffic, as it provides strong encryption for key exchanges and digital signatures.

Correct Answer: It uses a small key size

DES has a small key size of 56 bits, which makes it vulnerable to brute-force attacks.

Correct Answer: Two different inputs produce the same hash value

A collision occurs when two different inputs produce the same hash value, compromising the security of the hash function.

Correct Answer: ECC provides stronger encryption with smaller key sizes

ECC offers equivalent security to RSA with much smaller key sizes, making it more efficient for encryption and key exchange.

Correct Answer: To establish the identity of a sender or receiver

Digital certificates are used to verify the identity of the sender or receiver in a communication, ensuring that public keys belong to the intended party.

Correct Answer: RSA

RSA is commonly used for generating digital signatures, which provide authentication and ensure the integrity of a message.

Correct Answer: To define how encryption and decryption are performed on data blocks

Block cipher modes of operation define how data blocks are encrypted and decrypted using a block cipher algorithm like AES or DES.

Correct Answer: Brute-force attack

In a brute-force attack, the attacker tries every possible key until the correct one is found to decrypt the ciphertext.

Correct Answer: It allows for faster encryption and decryption

Symmetric encryption algorithms like AES are generally faster than asymmetric algorithms because they use the same key for both encryption and decryption.

Correct Answer: RSA

RSA relies on the mathematical difficulty of factorizing large prime numbers, which is the basis for its security.

Correct Answer: To ensure data integrity

Hashing is used to ensure data integrity by producing a fixed-length hash value from input data, allowing verification that the data has not been altered.

Correct Answer: Forward secrecy

Forward secrecy ensures that if long-term keys are compromised, past communication sessions remain secure because session keys are not derived from long-term keys.

Correct Answer: It encrypts data one bit at a time

Stream ciphers encrypt data one bit at a time, making them faster for real-time applications compared to block ciphers.

Correct Answer: RSA

RSA is a public key encryption algorithm, while AES, DES, and RC5 are symmetric encryption algorithms.

Correct Answer: To enhance the security of the hash by adding random data

Salting adds random data to the input before hashing, preventing attackers from using precomputed rainbow tables to crack the hash.

Correct Answer: 128 bits

AES has a fixed block size of 128 bits, regardless of the key length used in the encryption process.

Correct Answer: The attacker selects ciphertext to decrypt and obtain the corresponding plaintext

In a chosen-ciphertext attack, the attacker selects specific ciphertext to be decrypted, using the resulting plaintext to analyze the encryption method.

Correct Answer: AES

AES is a symmetric encryption algorithm, meaning the same key is used for both encryption and decryption.

Correct Answer: Diffie-Hellman

Diffie-Hellman is a key exchange protocol used in asymmetric encryption to establish a shared secret between two parties over an insecure channel.