[cryptography] Quality of HAVEGE algorithm for entropy?

stef s at ctrlc.hu
Fri Nov 29 10:06:07 EST 2013


On Fri, Nov 29, 2013 at 11:22:29AM +0100, Joachim Strömbergson wrote:
> What I was trying to say is that Havege running on MCUs (AVR, AVR32,
> PIC, PIC32, ARM Cortex M0 etc) where instructions in general takes the
> same number of cycles to execute and where caches are few (few levels),
> have simple or even no replacement policy (it is done by SW control),
> the assumptions in Havege is not really present. And that this change in
> physical setup _should_ affect the variance measured. But again, I
> haven't tested it yet.

howdy, i tried out the default haveged code found under:
http://www.irisa.fr/caps/projects/hipsor/misc.php#measure

on an arm cortex m3 stm32f2xx and streamed the results over uart and plotted
them here:
https://www.ctrlc.hu/~stef/stm32f2x-jitter.png

prefetch, data and instruction cache where enabled.

cheers,s

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