How do symmetric and asymmetric encryption differ?

Symmetric and asymmetric encryption primarily differ in their key management methods. In symmetric encryption, the same key is utilized for both encryption and decryption processes. This means that both the sender and receiver need to share this single secret key in a secure way. Conversely, asymmetric encryption employs a different mechanism involving a pair of keys: a public key and a private key. The public key can be shared openly and is used for encryption, while the private key is kept secret and is used for decryption. This dual-key system enhances flexibility in secure communications, as it allows anyone to encrypt a message using the public key, but only the holder of the private key can decrypt it.

This fundamental distinction highlights why the answer emphasizing that symmetric encryption uses one key while asymmetric encryption uses two keys is accurate. The other options relate to different aspects of encryption but do not correctly capture the primary difference in key usage. For instance, while asymmetric encryption might have certain advantages in key distribution, it is generally slower than symmetric encryption due to the complexity of operations involved. Additionally, the security levels of symmetric versus asymmetric encryption can vary significantly based on the context, and the methods for key generation for both are distinct rather than the same.