Which of the following is a characteristic of asymmetric encryption?

• A. Faster execution time
• B. Requires two keys
• C. Uses a single key for both encryption and decryption
• D. More vulnerable to brute-force attacks

Answer: (B)

Asymmetric encryption is characterized by the use of two keys: a public key and a private key. The public key is used for encryption, while the private key is used for decryption. This dual-key approach allows for secure communication, as the public key can be shared freely without compromising the security of the private key.

Each key has a different role, which enhances security in contrast to symmetric encryption, where the same key is used for both encrypting and decrypting data. The separate keys in asymmetric encryption also facilitate the implementation of digital signatures, ensuring both the confidentiality and authenticity of messages.

The other options don't correctly characterize asymmetric encryption. For instance, faster execution time pertains more to symmetric encryption, as it typically processes data more quickly due to the simpler key management. Additionally, the use of a single key for both encryption and decryption aligns with symmetric encryption. Lastly, while asymmetric encryption can be vulnerable to brute-force attacks, it is generally considered more secure against such attacks than symmetric encryption when properly implemented, particularly given the larger key sizes typically used.