You don’t have to be any kind of conspiracy theorist to recognise that powerful people have long used doctored images for a variety of purposes from selling papers to selling ideology (can you spot the difference?).
To make this very much more difficult, I propose using 3-D movies.
It’s well known to children reading a comic that when attempting to detect the almost imperceptible differences between two ‘alike’ images, all you have to do is ‘fuse’ these’ by crossing one’s eyes a little and visually superimposing them. Areas of disparity then all stand out simultaneously as twinkling regions.
Two small moviecameras mounted at interocular distance (~5cm) apart would be used to film every event. The two movies could later be superimposed by the viewer, possibly using a simple stereoscope, to see the scene in a single-viewpoint form of 3-D (although viewing one of the two movies in the conventional way would still be possible, of course).
These days, of course, Hollywood technologists can scan an actor’s face and insert it into a (2-D) movie so effectively that it looks as if he’s doing his own stunts. Without having scanned the objects or people in question, however, this insertion is pretty much impossible to fake convincingly in a sequence of stereo images: the twinkling effect is obvious. Thus the imagery is much more difficult to fake or manipulate.