Which cryptographic method uses two keys, a public and a private key?

Asymmetric encryption is a cryptographic method that utilizes a pair of keys: a public key and a private key. In this system, the public key is used to encrypt data, which can then only be decrypted by the corresponding private key. This functionality allows for secure communication where anyone can send an encrypted message using the public key, but only the holder of the private key can decrypt and read the message.

This two-key mechanism provides enhanced security for various applications, such as digital signatures and secure email, as it allows for confidentiality and authenticity. For instance, a sender can sign a document with their private key, and the recipient can verify the signature using the sender's public key, ensuring the document's integrity and origin.

In contrast, symmetric encryption employs a single key for both encryption and decryption, which makes key management more challenging. Hashing is not an encryption method but rather a technique used to securely store data by generating a fixed-size output (hash) from input data, which cannot be reversed back to the original data. Steganography involves hiding information within other non-secret data, which is distinct from both encryption and hashing approaches.