To make the collision work you need to produce two different files, both with some randomish looking junk in them. So if you can do that in a way where you can

To make the collision work you need to produce two different files, both with some randomish looking junk in them. So if you can do that in a way where you can substitute one of the files for the other without getting caught then you are almost for sure smart enough to also figure out a way to make the lengths the same.