Which type of encryption uses a shared key?

Symmetric encryption is characterized by the use of a shared key for both encryption and decryption processes. This means that the same key must be used by both the sender and the receiver to encrypt and decrypt the data, making it efficient for securing data when both parties can be trusted to keep the key confidential. Common examples of symmetric encryption algorithms include AES (Advanced Encryption Standard) and DES (Data Encryption Standard).

In contrast, public key encryption involves the use of two keys, a public key for encryption and a private key for decryption, which isn't applicable in this scenario. Asymmetric encryption refers to this method of using paired keys, which adds complexity and facilitates secure key exchange but does not utilize a shared key in the same way. Therefore, the nature of symmetric encryption as involving a shared secret distinguishes it clearly from these other encryption types.