Interesting train of thought, a potentially basic idea to combat this could be having a cryptographic algorithm used to sign each frame, basically set a specifi

Interesting train of thought, a potentially basic idea to combat this could be having a cryptographic algorithm used to sign each frame, basically set a specific value in one or more pseudo-random pixels each frame of a video, forcing a 1 or 0 in the least significant bit in a known pattern along with the signing identity of the original creator - an attacker without the private key wouldn't be able to successfully re-sign the video as they'd have no way of really knowing the original sequence, and they wouldn't have the signing key to be able to regenerate the original sequence or recreate it from the tampered frames. Unfortunately I am not a crypto expert but maybe a codec could check for signature pixels every frame in playback and provide a warning if no key signature is detected in realtime for any of the loaded frames if the user has a matching verification key. Either an attacker would maliciously blank or randomise the LSB which would show the entire video as unsigned, or the tampered portions would show up if and when the signature pixel chain is broken. I guess the issue would be around securely distributing verification keys that can verify both the signing identity and verify the correct sequence? But then that would put the ability to recreate the sequence in the hands of the attackers? Oh and I guess variable bitrates could cause issues. Damn this stuff is harder than I thought. There's probably a billion ways this wouldn't work and a thousand existing solutions?