[Cryptech Tech] ent for rosc entropy in the Xilinx FPGA

[Fredrik Thulin]

On Monday, December 08, 2014 10:03:06 PM Bernd Paysan wrote:
...
> > Optimum compression would reduce the size
> > of this 67121200 byte file by 0 percent.
> > 
> > Chi square distribution for 67121200 samples is 227.52, and randomly
> > would exceed this value 89.14 percent of the times.
> 
> That could be higher...

If it behaves like the avalanche noise sources I've been testing, it would 
likely rise a bit with more data (Joachim only had 67 Mbytes when he ran the 
tests it seems).

...
> > I'm doing extraktion of more data. And if anybody wants the current raw
> > data to do further analysis just tell me.
> 
> Sure, where can I get it?  A histogram plot over the bytes is the thing I do
> first to check if there's something odd; from the ent results, there
> probably isn't.

You've got a Novena, right? Maybe Joachim can send you a dump of what you need 
to get the rosc into your device.

If you are interested in more than the rosc, I would gladly make a prototype 
noise source board for you - although I'm out of PCBs at the moment. Are you 
going to 31c3?

/Fredrik