Your description is not clear. Do you mean you want to back up the database automatically?
Then, just use a CRON job which is just a simple PHP file that can create the backup for you.
Then, the other system can copy that file as needed. You would not want to use a post system to transfer your database. And, you would NOT care about encryption at all. If you have access to your database on the system is it hosted on, then you can use standard PHP/MySQL commands to back it up.
Here is a simple example:
$filename = 'Adem_database_backup_' . date('Y-m-d') . '.sql';
$result = exec('mysqldump DATABASE-NAME -u USER-NAME -p PASSWORD > ' . $filename);
This will create a full backup file of your database. You can alter this to just backup one table. There are many other ways to backup database tables, but, this is the easiest, in my humble opinion!
*** You have to enter your database name, the user and password for the database. Once this process is completed, you can transfer the file to the other machine using FTP if needed.
I hope this is what you are asking about.
( Oh, note I added the date-timestamp in the filename. This will not overwrite older backups, you may not want that to happen. You might want to remove the timestamp so it overwrites the backup file each time.)