Marlin Firmware Expert

I have a 3D printer with MKS Gen-L V1.0 with some modified version of Marlin and I am trying to modify the source code of Marlin in a way that only works with an encrypted gcode file. My plan was to use a symmetric encryption algorithm such as AES or DES to encrypt my gcode file in C or C++ with a key and use the same key in the Marlin code to decrypt the code on Arduino and continue printing as normal. I would like to hire an Marlin firmware expert about this issue.