Which of the following best describes symmetric encryption?

• A. It requires multiple public keys for data security
• B. It uses two different keys for encryption and decryption
• C. It employs the same key for both encryption and decryption
• D. It is a method of asymmetric encryption

Answer: (C)

Symmetric encryption is characterized by the use of a single key for both the encryption and decryption processes. This means that the same key must be shared and kept secret between the parties involved in the communication. The primary benefit of symmetric encryption is that it typically allows for faster processing and less computational overhead compared to asymmetric methods. Since both encryption and decryption operate using the same key, it simplifies the encryption process, making it efficient for large amounts of data.

To clarify why the other options do not apply: using multiple public keys pertains to asymmetric encryption, where pairs of keys (public and private) are utilized. The notion of two different keys for encryption and decryption explicitly describes asymmetric encryption as well, where the public key encrypts data and the private key decrypts it. Lastly, saying that symmetric encryption is a method of asymmetric encryption contradicts the fundamental principles of these two distinct encryption types.