> if I can't look at the source (all the way down) of your product and build it myself, it's not going to make the cut as a "secure" system
Other have already linked to https://www.fourmilab.ch/hotbits/hardware3.html and if your biggest concern is verifying it, then what could be simpler than detecting radioactive decay events?
Other have already linked to https://www.fourmilab.ch/hotbits/hardware3.html and if your biggest concern is verifying it, then what could be simpler than detecting radioactive decay events?