Is there a need for a service like this? (I've been looking for something interesting to build.)
Having unforgeable signatures on every image-capture device just in case some output file could be submitted as evidence in a civil case would be a privacy and safety _nightmare_, OTOH.
So it seems like if it comes from a security camera and you can say how it was recorded then that’s good, but if it’s video found on social media and you don’t know who recorded it then that should count against it.
I think before building anything, it might make sense to see what security cameras already do?