What does symmetric encryption rely on?

Symmetric encryption relies on a single key for both encryption and decryption, which is why the correct answer focuses on this aspect. In symmetric encryption, the same secret key is utilized by both the sender and the receiver to encode and decode the information. This method is efficient and allows for fast processing, which is vital when dealing with large volumes of data.

The key must be kept secret, as anyone with access to it can decrypt the messages. Because there is only one key shared between the parties involved, the challenge lies in securely distributing this key to prevent unauthorized access. Symmetric encryption includes algorithms such as AES (Advanced Encryption Standard) and DES (Data Encryption Standard), which are widely used in various applications.

Other options do not accurately represent the core principle of symmetric encryption; for instance, the concept of asymmetric keys refers to a different method where two keys—public and private—are used, highlighting the distinction between symmetric and asymmetric encryption methods.