Which type of encryption allows public and private keys for secure communication?

Asymmetric encryption is the approach that utilizes a pair of keys: a public key and a private key, making it suitable for secure communication. In this model, the public key can be shared openly and is used to encrypt messages, while the private key is kept secret and is used to decrypt messages that have been encrypted with the corresponding public key. This dual-key mechanism allows secure exchanges and ensures that only the intended recipient, who possesses the matching private key, can read the message.

This method enhances security by eliminating the need to share a single key between parties, which is a significant vulnerability in symmetric encryption. Symmetric encryption, while efficient for encrypting large amounts of data, relies on the same key for both encryption and decryption, making key distribution a major challenge. On the other hand, block and stream encryption refer to methods of encrypting data but do not specifically relate to the key management model that employs both public and private keys.