DIY Iris Scanning?

gadzook33 asks: "There have been rumors floating around about DIY iris scanning, using digital cameras for biometric security. Iris scanning presents a fantastic alternative to password-based authentication but hasn't really come to our desktops yet. I've looked around but can't find any concrete material on the subject. Is anyone doing this? Are there any efforts to develop open software for this sort of thing? Are patents holding things up? Given that passwords are an almost defunct technique for protecting data in certain situations, it would be nice to have an alternative."

Static Iris Scanning is useless, not dynamic

[iendedi]

While it is true that one could hold up a photo of your iris to a camera and spoof a static iris scanner, doing the same to a dynamic scanner is not practical.

What is a dynamic iris scanner? One that looks not only for the unique patterns of the eye, but also simultaneously measures retinal response to stimuli such as dimming and brightening of the display. This is much more difficult to spoof (you would essentially need to build a model of the target's eye that could respond to external stimuli and then hold that up to the scanner).

Combined with facial recognition, dynamic iris scanning is very potent. First it recognizes your face and then your eye and then the retinal response with stimuli that is timed to be somewhat random. Just don't try to log on after a night of pubbing.

How I would do it...

[cr0sh]

I would start out with a cheap USB web camera. First, I would hack it in some manner to allow it to macro-focus. I would go down to goodwill or a pawn shop and pick up the cheapest, most busted VHS video camera being sold. From this I should be able to get much of the optical components and the needed eyecup.

I would attempt to obtain a fake eyeball of some sort. While it wouldn't work perfectly, it would give me some sort of method by which to focus with. Mounted with some tape to the eyecup, and then positioned in front of the webcam, I would be able to determine the focus fairly quickly.

I would then set up some kind of "ring illumination", wherein I would create a "ring" of LEDs - red/green/blue/IR - through which the webcam would peer. Focussing again might have to be adjusted. This ring would be set up in such a fashion so that I could trigger which set(s) of LED's would be active at once - likely via USB control, too.

Once I had that set up, and focussing correct, I would then work on the software. For this DIY project, I would simply set things up to take multiple image captures of my own eye, process the images through some filters to reduce the information to just my iris (cue on the white of eyeball, and black of the pupil), then (in some manner), use these images to create an "eigeniris" image, some kind of "average" of all the images I took (over several days or months, in different levels/conditions, so as to have the best average available). Then, the software could take an image, compare it to the "eigeniris", determine if it falls within range, and use that to trigger or deny access (to whatever).

That would be the route I would take if I was doing this. Overall, the hardware portion seems the simplest to implement - the software is where you will bog down. Just like any other pattern recognition project, I would imagine...