Entropy from disks
Quoted 13 lines · David Schwartz
Quoted 10 lines · Chris Friesen
Oliver Xymoron wrote:
I'm not an expert in this field, so bear with me if I make any blunders obvious to one trained in information theory.
Quoted 5 lines
The current Linux PRNG is playing fast and loose here, adding entropy based on the resolution of the TSC, while the physical turbulence processes that actually produce entropy are happening at a scale of seconds. On a GHz processor, if it takes 4 microseconds to return a disk result from on-disk cache,
/dev/randomwill get a 12-bit credit.
Quoted 8 lines
Quoted 5 lines
In the paper the accuracy of measurement is 1ms. Current hardware has tsc precision of nanoseconds, or about 6 orders of magnitude more accuracy. Doesn't this mean that we can pump in many more bits into the algorithm and get out many more than the 100bits/min that the setup in the paper acheives?
In theory, if there's any real physical randomness in a timing source, the
more accuracy you measure the timing to, the more bits you get.
Not if the timing source is clocked at a substantially slower speed than the measurement clock and is phase locked. Which is the case.
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