I was about to mention rapid screenshoting as an exploit, but you took care of that. However, couldn't a rapid screenshoting application end up replacing the default screenshot function if this technique became commonplace? As the bar for using the vulnerability gets lower, the technique grows more and more useless. Maybe this can be modified to eliminate the exploit somehow (my thoughts go towards adding more randomness in some way or another)?
Even if it were to become a commonplace way to time-protect images, I can't really see Apple making their screenshotting functionality actually deal with it - they'd be doing it just to circumvent this simple security system, it wouldn't have any other benefits. On Android, though (and jailbroken iOS), I can definitely see people writing mods to break this right away.
I don't think that this technique (even in a more complicated form) could ever be exploit-proof. Even with more randomness or noise, a computer can ultimately compute the same averaging that our eyes are doing, and could always get the source image back.
There's an even easier exploit too: just record the screen with another device.
Comments
I was about to mention rapid screenshoting as an exploit, but you took care of that. However, couldn't a rapid screenshoting application end up replacing the default screenshot function if this technique became commonplace? As the bar for using the vulnerability gets lower, the technique grows more and more useless. Maybe this can be modified to eliminate the exploit somehow (my thoughts go towards adding more randomness in some way or another)?
Even if it were to become a commonplace way to time-protect images, I can't really see Apple making their screenshotting functionality actually deal with it - they'd be doing it just to circumvent this simple security system, it wouldn't have any other benefits. On Android, though (and jailbroken iOS), I can definitely see people writing mods to break this right away.
I don't think that this technique (even in a more complicated form) could ever be exploit-proof. Even with more randomness or noise, a computer can ultimately compute the same averaging that our eyes are doing, and could always get the source image back.
There's an even easier exploit too: just record the screen with another device.