"There is no algorithm that can generate entropy. Therefore any HRNG depends on input from some hardware device. It is necessary to calibrate the input device. For example, the entropy available from a soundcard depends on the input impedance, gain, bandwidth, and temperature. Calibration is not easy. It requires skill in a number of areas, including physics, electrical engineering, programming, and cryptography. However, just because it is hard is no excuse for skipping this step.
... My favorite proverb of all is the one that says for every proverb, there is an equal and opposite proverb. In this case, we should note that the proverb about not putting all your eggs in one basket is not necessarily a sound engineering principle. The right answer depends on the margin of error and on the per-basket failure rate. It also greatly depends on the chance of correlated, uncorrelated, and anti-correlated basket failures. Sometimes the best way to get your eggs from point A to point B is to put them all in one basket and take really good care of that basket.
... The phrase “random number generator” should be parsed as follows: It is a random generator of numbers. It is not a generator of random numbers."
Obligatory quote: http://dilbert.com/strip/2001-10-25 - "9, 9, 9, 9... -Are you sure that's random? -That's the problem with randomness: You can never be sure."
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John Denker wrote a page on RNGs, http://www.av8n.com/computer/htm/secure-random.htm
"There is no algorithm that can generate entropy. Therefore any HRNG depends on input from some hardware device. It is necessary to calibrate the input device. For example, the entropy available from a soundcard depends on the input impedance, gain, bandwidth, and temperature. Calibration is not easy. It requires skill in a number of areas, including physics, electrical engineering, programming, and cryptography. However, just because it is hard is no excuse for skipping this step.
... My favorite proverb of all is the one that says for every proverb, there is an equal and opposite proverb. In this case, we should note that the proverb about not putting all your eggs in one basket is not necessarily a sound engineering principle. The right answer depends on the margin of error and on the per-basket failure rate. It also greatly depends on the chance of correlated, uncorrelated, and anti-correlated basket failures. Sometimes the best way to get your eggs from point A to point B is to put them all in one basket and take really good care of that basket.
... The phrase “random number generator” should be parsed as follows: It is a random generator of numbers. It is not a generator of random numbers."
Obligatory quote: http://dilbert.com/strip/2001-10-25 - "9, 9, 9, 9... -Are you sure that's random? -That's the problem with randomness: You can never be sure."