What type of encryption uses a public key to encrypt data and a private key to decrypt it?

Public key encryption, also known as asymmetric encryption, utilizes a pair of keys: a public key and a private key. The public key is used to encrypt data, meaning it can be freely shared with anyone who needs to send a secure message. In contrast, only the corresponding private key, which is kept secret by the owner, can decrypt this data. This method enhances security because even if someone intercepts the encrypted data, they cannot decrypt it without access to the private key.

In contrast, symmetric key encryption relies on a single key for both encryption and decryption, which requires that both sender and receiver securely share this key beforehand. Hash encryption, on the other hand, is not an encryption method but rather a technique that converts data into a fixed-size hash value, usually for integrity verification, rather than confidentiality. Block encryption refers to the method of encrypting data in fixed-size blocks, but it can be either symmetric or public key; thus, it does not specifically describe the use of a public key for encryption.