Comment by gorgoiler

But what about if:

…the signature included the depth measured by the autofocus system across the image?

…or a tiny stereo image was included to capture depth?

…or a mini video in the ten seconds before and after the photo was taken?

…and the key is in a tamper proof HSM?

…and the key is deleted the moment the camera detects the case being taken apart?

I know that it is a losing battle to try to build such hardware when offline attackers have essentially infinite time to dismantle even the most elaborate systems — no such thing as an un breakable safe, only how long it takes to break into it, etc — but I feel these are valid counter measures, are they not?