From: Stephan Mueller <smueller@chronox.de>
To: "Łukasz Stelmach" <l.stelmach@samsung.com>
Cc: Matt Mackall <mpm@selenic.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ray Jui <rjui@broadcom.com>,
Scott Branden <sbranden@broadcom.com>,
bcm-kernel-feedback-list@broadcom.com,
Kukjin Kim <kgene@kernel.org>,
Krzysztof Kozlowski <krzk@kernel.org>,
Florian Fainelli <f.fainelli@gmail.com>,
Markus Elfring <elfring@users.sourceforge.net>,
Matthias Brugger <mbrugger@suse.com>,
Stefan Wahren <wahrenst@gmx.net>,
linux-crypto@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Subject: Re: [PATCH 1/2] hwrng: iproc-rng200 - Set the quality value
Date: Thu, 14 May 2020 22:20:26 +0200 [thread overview]
Message-ID: <4493123.C11H8YMYNy@tauon.chronox.de> (raw)
In-Reply-To: <20200514190734.32746-2-l.stelmach@samsung.com>
Am Donnerstag, 14. Mai 2020, 21:07:33 CEST schrieb Łukasz Stelmach:
Hi Łukasz,
> The value has been estimaded by obtainig 1024 chunks of data 128 bytes
> (1024 bits) each from the generator and finding chunk with minimal
> entropy using the ent(1) tool. The value was 6.327820 bits of entropy
> in each 8 bits of data.
I am not sure we should use the ent tool to define the entropy level. Ent
seems to use a very coarse entropy estimation.
I would feel more comfortable when using other measures like SP800-90B which
even provides a tool for the analysis.
I understand that entropy estimates, well, are estimates. But the ent data is
commonly not very conservative.
[1] https://github.com/usnistgov/SP800-90B_EntropyAssessment
Ciao
Stephan
WARNING: multiple messages have this Message-ID (diff)
From: Stephan Mueller <smueller@chronox.de>
To: "Łukasz Stelmach" <l.stelmach@samsung.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Scott Branden <sbranden@broadcom.com>,
Matthias Brugger <mbrugger@suse.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Matt Mackall <mpm@selenic.com>,
linux-kernel@vger.kernel.org,
Krzysztof Kozlowski <krzk@kernel.org>,
linux-samsung-soc@vger.kernel.org,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Kukjin Kim <kgene@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Stefan Wahren <wahrenst@gmx.net>, Ray Jui <rjui@broadcom.com>,
bcm-kernel-feedback-list@broadcom.com,
Markus Elfring <elfring@users.sourceforge.net>,
linux-arm-kernel@lists.infradead.org,
linux-crypto@vger.kernel.org
Subject: Re: [PATCH 1/2] hwrng: iproc-rng200 - Set the quality value
Date: Thu, 14 May 2020 22:20:26 +0200 [thread overview]
Message-ID: <4493123.C11H8YMYNy@tauon.chronox.de> (raw)
In-Reply-To: <20200514190734.32746-2-l.stelmach@samsung.com>
Am Donnerstag, 14. Mai 2020, 21:07:33 CEST schrieb Łukasz Stelmach:
Hi Łukasz,
> The value has been estimaded by obtainig 1024 chunks of data 128 bytes
> (1024 bits) each from the generator and finding chunk with minimal
> entropy using the ent(1) tool. The value was 6.327820 bits of entropy
> in each 8 bits of data.
I am not sure we should use the ent tool to define the entropy level. Ent
seems to use a very coarse entropy estimation.
I would feel more comfortable when using other measures like SP800-90B which
even provides a tool for the analysis.
I understand that entropy estimates, well, are estimates. But the ent data is
commonly not very conservative.
[1] https://github.com/usnistgov/SP800-90B_EntropyAssessment
Ciao
Stephan
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-05-14 20:20 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20200514190737eucas1p18ccdddb185ea7611683a6859e17bc721@eucas1p1.samsung.com>
2020-05-14 19:07 ` [PATCH 0/2] Set the quality value for two HW RNGs Łukasz Stelmach
2020-05-14 19:07 ` Łukasz Stelmach
[not found] ` <CGME20200514190738eucas1p2695c0d8af064ee702209ca03696ef438@eucas1p2.samsung.com>
2020-05-14 19:07 ` [PATCH 1/2] hwrng: iproc-rng200 - Set the quality value Łukasz Stelmach
2020-05-14 19:07 ` Łukasz Stelmach
2020-05-14 20:20 ` Stephan Mueller [this message]
2020-05-14 20:20 ` Stephan Mueller
[not found] ` <CGME20200514221852eucas1p2bea169d0b4467b0ec9e195c6ac58a08a@eucas1p2.samsung.com>
2020-05-14 22:18 ` Lukasz Stelmach
2020-05-14 22:18 ` Lukasz Stelmach
2020-05-15 8:32 ` Stephan Mueller
2020-05-15 8:32 ` Stephan Mueller
[not found] ` <CGME20200515090647eucas1p21018edfd835730c9a68dcb186349ee74@eucas1p2.samsung.com>
2020-05-15 9:06 ` Lukasz Stelmach
2020-05-15 9:06 ` Lukasz Stelmach
[not found] ` <CGME20200515090158eucas1p1b653fc50f1ad4f0f6c92525ab3188d45@eucas1p1.samsung.com>
2020-05-15 9:01 ` Lukasz Stelmach
2020-05-15 9:01 ` Lukasz Stelmach
2020-05-15 9:10 ` Stephan Mueller
2020-05-15 9:10 ` Stephan Mueller
[not found] ` <CGME20200515110002eucas1p136759396d9b61f214d1f14856c009501@eucas1p1.samsung.com>
2020-05-15 10:59 ` Lukasz Stelmach
2020-05-15 10:59 ` Lukasz Stelmach
[not found] ` <CGME20200514190740eucas1p293129b2ef3ba706652a9327e55db9649@eucas1p2.samsung.com>
2020-05-14 19:07 ` [PATCH 2/2] hwrng: exynos " Łukasz Stelmach
2020-05-14 19:07 ` Łukasz Stelmach
2020-05-14 20:20 ` Stephan Mueller
2020-05-14 20:20 ` Stephan Mueller
[not found] ` <CGME20200519212617eucas1p1b6e7af0ecb894896b165601fafd6abe8@eucas1p1.samsung.com>
2020-05-19 21:25 ` [PATCH v2 0/2] Set the quality value for two HW RNGs Łukasz Stelmach
2020-05-19 21:25 ` Łukasz Stelmach
[not found] ` <CGME20200519212619eucas1p22fa5d3db2521096dc4b79f6e53016d17@eucas1p2.samsung.com>
2020-05-19 21:25 ` [PATCH v2 1/2] hwrng: iproc-rng200 - Set the quality value Łukasz Stelmach
2020-05-19 21:25 ` Łukasz Stelmach
2020-05-20 6:23 ` Stephan Mueller
2020-05-20 6:23 ` Stephan Mueller
[not found] ` <CGME20200520091043eucas1p15ecae108007382a95b01e42241cc7a26@eucas1p1.samsung.com>
2020-05-20 9:10 ` Lukasz Stelmach
2020-05-20 9:10 ` Lukasz Stelmach
2020-05-20 9:18 ` Stephan Mueller
2020-05-20 9:18 ` Stephan Mueller
[not found] ` <CGME20200520104448eucas1p122e9a8ed84d5276a1b796e10ef5e1964@eucas1p1.samsung.com>
2020-05-20 10:44 ` Lukasz Stelmach
2020-05-20 10:44 ` Lukasz Stelmach
2020-05-20 11:53 ` Stephan Mueller
2020-05-20 11:53 ` Stephan Mueller
2020-05-20 12:00 ` Krzysztof Kozlowski
2020-05-20 12:00 ` Krzysztof Kozlowski
2020-05-20 12:11 ` Stephan Mueller
2020-05-20 12:11 ` Stephan Mueller
[not found] ` <CGME20200520143211eucas1p21bd93be5c62726aa715db05bb6e7119b@eucas1p2.samsung.com>
2020-05-20 14:31 ` Lukasz Stelmach
2020-05-20 14:31 ` Lukasz Stelmach
2020-05-20 8:18 ` Kamil Konieczny
2020-05-20 8:18 ` Kamil Konieczny
2020-05-21 11:00 ` Stefan Wahren
2020-05-21 11:00 ` Stefan Wahren
[not found] ` <CGME20200521191415eucas1p2d112a86171b23dcf255e7da53a56f4f3@eucas1p2.samsung.com>
2020-05-21 19:14 ` Lukasz Stelmach
2020-05-21 19:14 ` Lukasz Stelmach
2020-05-23 18:46 ` Stephan Müller
2020-05-23 18:46 ` Stephan Müller
[not found] ` <CGME20200519212621eucas1p13279db41d930b69e115972463c994a37@eucas1p1.samsung.com>
2020-05-19 21:25 ` [PATCH v2 2/2] hwrng: exynos " Łukasz Stelmach
2020-05-19 21:25 ` Łukasz Stelmach
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