Which type of encryption involves a public and private key?

Asymmetric encryption is characterized by the use of a pair of keys: a public key and a private key. In this method, the public key is shared openly and can be used by anyone to encrypt data intended for the key’s owner, while the private key is kept secret by the owner and is used to decrypt the data that was encrypted with the corresponding public key. This dual-key mechanism enhances security, as the private key does not need to be transmitted or shared, reducing the risk of interception.

In contrast, symmetric encryption utilizes a single key for both encryption and decryption, meaning that both parties must securely exchange the key beforehand. Hash encryption is not a form of encryption in the traditional sense, but rather a way to create a fixed-size hash value from any size of input data, which is useful for data integrity verification. Block encryption refers to techniques that operate on fixed-size blocks of data, but this can either include symmetric or asymmetric methods of encryption. The use of public and private keys distinctly marks asymmetric encryption as the correct choice in this context.