The distinguishing feature of asymmetric encryption is that it uses distinct keys for encryption and decryption. Specifically, it involves a public key for encryption and a private key for decryption. This dual-key mechanism ensures that even if the encryption key (public key) is widely distributed, the decryption key (private key) remains secure and confidential. This is in contrast to symmetric encryption, which uses the same key for both encryption and decryption (IAPP, Certified Information Privacy Technologist (CIPT) materials).