Re: [PATCH 1/2] hwrng: iproc-rng200 - Set the quality value

From: Stephan Mueller
Date: Fri May 15 2020 - 05:11:02 EST


Am Freitag, 15. Mai 2020, 11:01:48 CEST schrieb Lukasz Stelmach:

Hi Lukasz,


As I mentioned, all that is or seems to be analyzed here is the quality of the
cryptographic post-processing. Thus none of the data can be used for getting
an idea of the entropy content.

That said, the ent value indeed looks too low which seems to be an issue in
the tool itself.

Note, for an entropy assessment commonly at least 1 million traces from the
raw noise source are needed.

See for examples on how such entropy assessments are conducted in the LRNG
documentation [1] or the Linux /dev/random implementation in [2]

[1] appendix C of https://www.chronox.de/lrng/doc/lrng.pdf

[2] chapter 6 of https://www.bsi.bund.de/SharedDocs/Downloads/EN/BSI/
Publications/Studies/LinuxRNG/LinuxRNG_EN.pdf

Ciao
Stephan