As someone with a passing interest in infosec and cryptography, I'm sceptical of the long-term viability of this kind of product; it only takes one person successfully extracting a signing key to undermine the entire project.
[0] https://leica-camera.com/en-int/news/partnership-greater-trust-digital-photography-leica-and-content-authenticity-initiativeI just think there is a world of difference between "certainty" and "plausibility" when it comes to videos on the internet. Yes, state actors might circumvent it, and skepticism should remain, but there is a world of difference between North Korea trying to convince me of some political scandal, and Pepsi Co trying to convince me that someone I trust loves Pepsi.
There might be a specialised line of cameras for forensics that signs the output and has lidar to detect when the camera is pointed at a screen, but the average person won’t have a camera with this kind of crypto. It would just be too easy for hackers to extract the keys from.
they're already locked down as-is.