What characterizes an asymmetric key (public key) encryption technique?

Asymmetric key encryption, also known as public key encryption, is characterized by the use of two different keys: a public key, which is used for encryption, and a private key, which is used for decryption. This dual-key system facilitates secure communication, as anyone can use the public key to encrypt a message, but only the holder of the corresponding private key can decrypt it. This method ensures that even if the public key is widely known, the message remains secure because the private key is kept secret.

This is in stark contrast to symmetric key encryption, where the same key is required for both encryption and decryption. Because of the different keys, asymmetric encryption is often used in scenarios such as securing email communication and establishing secure connections over the internet, such as HTTPS.

The other options reference different concepts that do not accurately reflect the defining characteristics of asymmetric encryption. Binary code and data storage are not central to the fundamental operation of asymmetric encryption techniques.