[Cryptography] Of writing down passwords

[Christian Huitema]

> | Can you post a demo of that?
> | 
> | Many of us have seen the Blade Runner movie scene where a photo is
> | magnified to show who took it via a captured reflection.  But whenever
> | I've tried something similar, the pixels are just too big and they
> | fuzz out.  I wasn't aware that e.g. laptop/phone cameras had good
> | enough optics and resolution to use reflections from eyes or
> | eyeglasses to read handwriting that's out of view of the camera.
>
>
> Lookup "PlaceRaider" -- it's three year old technolgy so project
yourself forward in time to the present...

Place Raider is about 3D reconstruction from multiple pictures. John's
question was about "reading reflections on eyes or glasses." We are not
quite there yet. With a 1080p camera at 1 meter from your eyes, the eyes are
typically 30 pixels wide, and the iris 10 pixels. This is not enough to read
something. Even with the 41 Mpixels camera of the Nokia Lumia 1020, you will
get less than 150 pixels for the eyes and less than 50 for the iris. Getting
there, but not quite.

On the other hand, I was surprised when a friend took a photo of my office
with the Lumia 1020, and then showed me that he could read the handwritten
note pinned on the wall. 

-- Christian Huitema