Which type of encryption commonly uses a single key to encrypt and decrypt messages securely?

Symmetric cryptography utilizes a single key for both the encryption and decryption of messages. This means that the same key must be shared between the sender and the receiver to ensure that the encrypted information can be securely accessed and understood by the intended recipient. The efficiency and speed of symmetric encryption make it particularly suitable for large volumes of data.

In symmetric cryptography, the key must remain confidential; if it is compromised, the security of the encrypted data is at risk. This form of encryption is widely used in various applications, such as securing communications, encrypting files, and protecting data in transit.

By contrast, asymmetric cryptography uses a pair of keys — a public key for encryption and a private key for decryption, which involves a more complex algorithm and generally slower performance. Digital signatures are used to verify authenticity and integrity rather than secure communications directly. Hashing produces a fixed-size string from input data but does not involve keys for encryption or decryption, as its primary purpose is to ensure data integrity.