PGP encryption

I have a website that use wordpress, actually the client upload a file in json or excel via an ftp and with a script it import the information to a database under PHP myadmin in WordPress or with a cron we have a export every 5 mins json or excel depend on the script we are using. But we are looking to secure the procedure where the client upload the file as a pgp then we use a script to extract it to json or excel so that our script can import it to the database and same for export, our script export the file in a folder then we concert it in pgp. We use Cpanel environement

Please note that we have two type of script it either json or excel.