[Flash] trying to get away from 777!

Okay so I have I flash website that reads an XML file for its content.

I have a flash CMS that calls PHP files to change the XML files.

I can only read in the XML files from flash if their chmod unix file permissions are set to 777.

However, this allows ANYONE to read/write/execute the XML files. This is NOT what I want.

Does anyone know how to get data into flash without have the file permissions set to 777?