On Thu, Mar 13, 2014 at 9:38 PM, Jack Scott <jack.scott.public@gmail.com> wrote:
BIP: XX
Title: Physical key / edge detection software and PIN to generate a Bitcoin private key
Author: Jack Scott
Status: Idea
Type: Standard Track
Created: 13-3-2014

Abstract:
A method is proposed to generate a Bitcoin private key by using a physical key in conjunction with image recognition software and a PIN.  Use edge detection software applied to incoming video feed to convert the shape of a physical key into an equation that describes the key.  The hash of the key's equation plus a user generated five digit pin can then be used to create a Bitcoin private key.


Interesting idea, though as Wladimir mentioned, a real-world "key" is much less secure than a Bitcoin/PGP "key", though in this case, I could see your physical/visual "key" being any complex, high-contrast image (like a Motion Tracking Target: https://www.google.com/search?q=tracking+markers&tbm=isch), if just using edge-detection (a high-contrast image would help make low-light or out-of-focus shots still able to be detected), though like a QR-code, it should probably have calibration markers in the corners to specify orientation (would help decoding a skewed or rotated image) and the standard should enforce some minimum level of complexity to prevent really simple and easy-to-reproduce/steal keys .

Though if you're getting to that level of complexity, you might as well just have a QR code of the private key.

Brooks