What's the difference then between taking a picture or using a large number or string?
Well...I guess I was thinking there wouldn't be any formulas/patterns/computer-generated random numbers involved (which really aren't random when you get down to it). In a sense, it would approach "true" random numbers if the picture is "noisy" enough. I
suppose it could be a key that is limited only in size by the complexity/size of the picture. Maybe RSA is stronger than that, I don't know. Again, I haven't done a great deal of research on it yet, and I confess I am not a mathematician.