@wyattbiker 's example is very relevant, one must replace open with open_encrypted or, I prefer with a password
func save(content):
var file = FileAccess.open_encrypted_with_pass("user://save_game.dat", FileAccess.WRITE, "my secret password!")
file.store_string(content)
func load():
var file = FileAccess.open_encrypted_with_pass("user://save_game.dat", FileAccess.READ, "my secret password!")
var content = file.get_as_text()
return content
You could also show your script for hex_encode, it’s better if we know what you’ve got so far.