Restricting files to uploads only

Hello, new user here.

I read that the encryption app will encrypt files on the external source something that I am looking to avoid.

Is it possible to have users who are outside of my company upload files securely?

By sending a link to a shared folder and securely encrypt the file once uploaded (data at rest)?

Looking for the procedure to be encrypted but transparent to the user except clicking the link, providing username/password and uploading the file.

The entire transmission require encryption end to end. Is this possible with ownCloud?

Can you clarify?

Do you want your files on external storage to be encrypted or don’t you want that?

Do you want to create users, share folders to them, and let them upload in to these folders files that will be encrypted?