[mpascale00]

Without having read into this deeper, it sounds like someone could take an original video which has this code embedded as small fluctuations in luminance over time and edit it or produce a new video, simply applying the same luminance changes to the edited areas/generated video, no? It seems for a system like this every pixel would need to be digitally signed by the producer for it to be non-repudiable.

[crazygringo]

Exactly, that is my question too. If you can detect the lighting variations to read and verify the code, then you can also extract them, remove them, reapply to the edited version or the AI version... varying the level of global illumination in a video is like the easiest thing to manipulate.

Although there's a whole other problem with this, which is that it's not going to survive consumer compression codecs. Because the changes are too small to be easily perceptible, codecs will simply strip them out. The whole point of video compression is to remove perceptually insignificant differences.

[janaagaard]

As I understand it, the brilliant idea is that the small variantions in brightness of the pixels look just like standard noise. Distinguishing the actual noise from the algorithm is not possible, but it is still possible to verify that the 'noise' has the correct pattern.

[tripdout]

The code embedded into the luminosity is sampled from a distribution resembling the noise already present in the video.

Plus, the code gives information about the frame it's embedded into, so you still have more work to do.

[mustyoshi]

Doesn't this just fall apart if a video is reencoded? Something fairly common on all video platforms.

[Palmik]

The code could be cryptographically derived from the content of the video. For simplicy, imagine there are subtitles baked into the video and the code is cryptographically derived from those.

[TeeMassive]

Not if you encode a cryptographic signature in the watermark

[yapyap]

what would that change

[gorkish]

So what if your adversary relays your encrypted message along another channel?

[lowbloodsugar]

Academics presenting the opening move in a game of white hat / black hat thinking the game is over after one turn.