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Comment Re:Can someone help explain "perfect" randomness? (Score 1) 128

I'm assuming that when they do one of those distribution plots of the output values (the ones that show clear patterns for pseudo random generators when run for long enough) they can prove that the distribution is totally uniform, and with time as a further axis, every attempt achieves that even distribution in a different sequence. That implies they can account for, or negate the impact of, every potential variable in the system.

Ah, no. That is totally worthless for this purpose. For example, the Mersenne Twister MT19997 passes this test perfectly, but with a few KB of its output you can predict all further output. Incidentally, only really bad and outdated PRNGs show such patterns. These days, statistical measurements are essentially useless to prove randomness. But these are Physicists, so they may not understand that. What you need is mathematical proof. Obviously, you can never get that for a physical system because that would need a perfect model of the world.

Comment Re:Can someone help explain "perfect" randomness? (Score 2) 128

The problem is for crypto, you need high per-bit entropy (or rather high per-bit unpredictability under reasonable conditions). But all this means is that you gather, say, 10kBit from your generator and then make a 256 bit key from that using a mixing process. Crypto-hashes are perfect for that. A CPRNG already does something like that for you and you just put in the 10kBit (or more) as seed.

Comment Yes. So? (Score 1) 93

It comes as absolutely no surprise that when you can execute code on a device, you may be able to gather fingerprints from other code running on that device. You get very little from that though. Basically the only useful case is if one website generates a specific usage pattern, another one may be able to detect that. But you could have gotten the same thing by just having the two sites communicate directly. Yes, there is a covert channel. No, it is not one that matters.

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