I've seen tons of examples about how to encrypt a string using RSA encryption but doing so at the file level seems to have sparse examples.
I understand that the file is actually encrypted using a symmetric algorithm and only the symmetric key is encrypted using the asymmetric method and that encrypted key is packaged with the data. I just can't see any good examples of this that I know will work with an open standard.
What I really want to know is how can I ensure I implement this so that it conforms to the explanation found in the attached file? I need to be able to send files to the bank and make sure they can decrypt them properly.