What is the key characteristic of symmetric encryption?

The key characteristic of symmetric encryption is that it uses one key for both encryption and decryption. This means that the same key is employed to encrypt plaintext into ciphertext and to decrypt the ciphertext back into plaintext. This method provides a straightforward mechanism for securing data, as only one key must be managed by both the sender and the recipient to unlock the encrypted information.

Symmetric encryption is widely used due to its efficiency in processing. Because it relies on a single key, it can often execute faster than asymmetric encryption, which utilizes a pair of keys (public and private). In this context, the requirement of only one key minimizes the complexity of the key management process as compared to systems that would necessitate multiple keys or different keys for encryption and decryption.