What type of keys does public key encryption use?

Public key encryption relies on a system of two keys: a public key and a private key. The public key is used to encrypt data, making it possible for anyone to send secure messages. However, only the corresponding private key, which is kept secret by the receiver, can decrypt that data. This dual-key system ensures that only the intended recipient, who possesses the private key, can access the encrypted information.

This method significantly enhances security in communication, as the public key can be shared openly without compromising the private key. Consequently, if someone wants to send a secure message, they can use the public key of the recipient to encrypt their message, ensuring that only the recipient can decrypt it with their private key. This characteristic enables a wide range of secure applications in cybersecurity, such as secure email communication, digital signatures, and more.

Other answer choices do not align with the fundamental principles of public key encryption, as they either suggest using only one key or keys that do not function within this encryption mechanism.