What is the main feature of asymmetric encryption?

Asymmetric encryption is characterized by the use of a pair of keys: a public key and a private key. The primary feature of this encryption method is that when a sender wishes to securely transmit information to a recipient, they will encrypt the message using the recipient's public key. This ensures that only the recipient, who possesses the corresponding private key, can decrypt and access the message content.

Using the recipient's public key for encryption is essential because it allows anyone to send a secure message to the recipient, while only the recipient can decrypt it with their private key, ensuring confidentiality and security in communication. This mechanism is crucial for establishing secure channels in various applications, including email encryption, secure file transfer, and digital signatures.

The other options misunderstand the asymmetric encryption process regarding key usage and functionality, which is central to this cryptographic approach.