I have a use-case where I am trying to collect crucial data with a web beacon/tracking pixel. I'm trying to create something similar to what SpotX does to verify how much of a video ad the user watched. They do it by placing a beacon at certain times of the video with a view_percent field indicating the % of how much the user watched. For example, in a 1 minute video they would place a beacon at 12 seconds with view_percent set to 20 which then lets their server know that the user has watched 20% of the video.
But the user could just modify the beacon and change the view_percent to 100, how could I prevent that or verify that the data hasn't been tamperedwith?