Re: grabbed video as a source of entropy
At 06:53 PM 9/24/99 -0700, Eugene Leitl wrote: I've recently aquired a video camera (bttv-based 3Com Bigpicture, can do 30 fps true color 640x480). I've noticed that under certain conditions images can become quite noisy. Does anyone has data on the amount and quality of the entropy produced? Even if I had the same hardware, perhaps the tolerances on my ADCs are different from yours. And illumination levels will affect certain kinds of noise. The point: Measure it. Use Shannon's entropy formula, for instance. I wouldn't mind any pointers to sources extracting, say, LSB from grabbed frames. Distill (irreversibly compress, e.g., by xor'ing several words together) your data. Measure again; distill again until 1 bit/baud. Hash before use. Any OTP tool should facilitate or automate these steps.
Re: grabbed video as a source of entropy
David Honig writes: Even if I had the same hardware, perhaps the tolerances on my ADCs are different from yours. And illumination levels will affect certain kinds of noise. Sure, but the entropy generation rate will be in any case higher than stuff coming from /dev/dsp The point: Measure it. Use Shannon's entropy formula, for instance. I'm not very well versed in such matters, and pressed for time in my day/night job. I wouldn't mind any pointers to sources extracting, say, LSB from grabbed frames. Distill (irreversibly compress, e.g., by xor'ing several words together) your data. Measure again; distill again until 1 bit/baud. Hash before use. I was looking for sources performing such steps. And I wouldn't want to crypto-hash lest the raw entropy gets debased by hidden algorithmic order. Any OTP tool should facilitate or automate these steps.
Re: grabbed video as a source of entropy
See http://lavarand.sgi.com/ John
