The most common asymmetric encryption algorithm (RSA) can only encrypt a plaintext of limited size. Depending on padding scheme, a 2048 bit RSA key can encrypt

The most common asymmetric encryption algorithm (RSA) can only encrypt a plaintext of limited size. Depending on padding scheme, a 2048 bit RSA key can encrypt a message of up to ~245 bytes. Typically to securely encrypt a message you use symmetric key encryption. Then to allow a third party to decrypt that message, you encrypt the symmetric key using the third party's asymmetric key.