What distinguishes symmetric encryption from asymmetric encryption?

The correct distinction between symmetric and asymmetric encryption is that symmetric encryption uses a single key for both encryption and decryption, while asymmetric encryption employs a pair of keys: a public key for encryption and a private key for decryption. This fundamental difference shapes how these two types of encryption are utilized in practice.

In symmetric encryption, the same key must be shared between the communicating parties, which can be both efficient and faster in terms of processing speed, making it suitable for encrypting large volumes of data. However, the central challenge lies in the secure distribution of that single key, as anyone with access to it can decrypt the information.

Asymmetric encryption, on the other hand, enhances security by using two different keys. This mechanism not only facilitates secure key exchange (since the public key can be shared openly) but also provides features like digital signatures for authentication and integrity verification.

The other options, while they touch upon aspects of encryption, do not correctly capture the defining characteristic that separates symmetric from asymmetric encryption.