They address the security possibilities in the paper:
> Our current implementation does not account
for security. However, to secure the wireless link between
the camera and reader, we can leverage the fact that our
digital core processes the PWM signal. Each wireless
camera can be assigned a unique pseudo random security
key. Based on this key, the camera’s digital core can
modulate the width of the PWM-encoded pixel value
using an XOR gate. The reader, which knows the security
key, can map the received data to the desired pixel values
by performing the analogous operation.
If the static image could be somehow "bankswitched", "shifted" or updated... I am thinking a huge one time pad. The problem is doing it power effeciently of course.
Thinking about, the main problem will be the penguin problem [1]. Which for a video is even worse as if a shape is moving, from seeing the pixels that are changing you can tell most of what is going on.
> Our current implementation does not account for security. However, to secure the wireless link between the camera and reader, we can leverage the fact that our digital core processes the PWM signal. Each wireless camera can be assigned a unique pseudo random security key. Based on this key, the camera’s digital core can modulate the width of the PWM-encoded pixel value using an XOR gate. The reader, which knows the security key, can map the received data to the desired pixel values by performing the analogous operation.