Messages in this thread | | | From | Peter Monta <> | Subject | Re: Continuing /dev/random problems with 2.4 | Date | Fri, 1 Feb 2002 19:30:27 -0800 (PST) |
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H. Peter Anvin wrote:
> However, those aren't the main failure modes you need to be concerned > with. Antenna effects may actually be your biggest problem -- picking > up deterministic signals from other parts of the system.
David Wagner wrote:
> For instance, is there a risk that the audio data you read is strongly > correlated to 60Hz mains noise in some scenarios? ...
I don't think predictable elements in the audio hurt anything. So long as there is a noise component, things are fine.
Take the case of a half-full-scale 60 Hz sine wave plus a tiny bit of noise. No problem---each sample would still be worth 0.1 bit because the attacker can only guess the 60 Hz part: subtract this out and you've still got unpredictable noise. Same deal with crosstalk between channels, so long as it's reasonably small, say -20 dB or better (as it will be with any sane sound chip).
> [ audio-entropyd ]
Aha, nothing new under the sun.
Cheers, Peter Monta - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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