[sdiy] analog loses another niche

[Tim Parkhurst]

On Wed, Jun 30, 2010 at 9:48 PM, Dave Manley <dlmanley at sonic.net> wrote:
<snip>
>
> So...I went and looked to see if Cavium had a patent on their TRNG, and
> indeed they do.  They use a bunch of ring oscillators (64 in one example),
> built out of very weak transistors, that are in a digitally noisy
> environment, thereby causing the oscillators to be extremely jittery, as a
> source of entropy.  They sample the oscillators and feed the result into a
> cryptographic hash such as SHA-1 (although the patent indicates you could
> use an LFSR).  The output of the cryptographic hash by it self is 'random'
> enough to pass most any test without the ring oscillators being fed into its
> state variable.
>
> Rings a bell - doesn't someone in the sdiy community make an LFO whose
> output is the sum of six inverter based oscillators set to different
> frequencies?
>
> -Dave
>

Well heck, if you want random just monitor the frequency of an old Moog 901 VCO.

Tim (the face rings a bell... ouch) Servo
-- 
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings