What is public key encryption?

Public-key cryptography, also known as asymmetric cryptography, uses a pair of keys: a public key, which may be widely distributed, and a private key, which is known only to the owner. The public key is used for encryption, and the private key is used for decryption. A common use is secure communication, where the sender encrypts a message using the recipient's public key, and only the recipient can decrypt it using their private key. It's also used for digital signatures, where the sender encrypts a hash of the message with their private key, and anyone can verify the signature using the sender's public key, ensuring authenticity and integrity.