I had similar project going where program executable had to had unique key in it before all users downloaded.
My approach to this was to take and compile 4 different excecutables with different known keys in them, then using hexedit find differences between those files. Knowing where each difference was I was able to write relatively small script ( in php ) which used single compiled file and replaced key inside of it before it was served to user.

Maybe similar strategy could be used here.
To generate binaries with unique keys, record those keys to database.

Then it would be in human hands to get bin images inside controllers.