Quote from: CIYAM on July 09, 2014, 04:44:03 PM

I like the idea of taking a random photo (with a camera that has no internet capabilities) and then downloading the photo to an offline computer and taking a SHA256 of the photo file.

Easy to do - and hard to screw up IMO (you could attach a simple web cam to the offline computer to make this even easier).

Of course that should work just fine, but I don't think there is really a good way to audit it. You have have to trust the camera.

That's the beauty of the card method, or dice, or something physical. You personally can control the influences on the physical item, and keep a record of the state. Then you can verify using different hardware and software setups that the resultant public keys and hashes come out the same. With the camera method, you have to trust the manufacturer of the camera to not backdoor the chips.

And on the card method, perhaps just adding a second deck would increase the bitspace enough so even really terrible shuffling bias would still yield computationally secure results.

Or we could all build dice-o-matics --> http://www.youtube.com/watch?v=7n8LNxGbZbs