[openssl-project] Entropy seeding the DRBG

[Oracle]

I can conform that it is measured in bits per sample size (in this case bytes).  The estimate is very low and this is not a great source.

We can explore other options and I should be able to spare some time over ICMC to assist.  I’m not well versed in VMS though.


Pauli

> On 30 Apr 2018, at 12:00 pm, Richard Levitte <levitte at openssl.org> wrote:
> 
> In message <20180430.164908.1424770216194967097.levitte at openssl.org> on Mon, 30 Apr 2018 16:49:08 +0200 (CEST), Richard Levitte <levitte at openssl.org> said:
> 
> levitte> In message <20180430.152609.587396153749337701.levitte at openssl.org> on Mon, 30 Apr 2018 15:26:09 +0200 (CEST), Richard Levitte <levitte at openssl.org> said:
> levitte> 
> levitte> levitte> In message <20180430131000.GA25216 at roeckx.be> on Mon, 30 Apr 2018 15:10:01 +0200, Kurt Roeckx <kurt at roeckx.be> said:
> levitte> levitte> 
> levitte> levitte> kurt> The comment about not hashing it is if you want to use the tool to
> levitte> levitte> kurt> do entropy estimation. Hashing it will not increase the entropy,
> levitte> levitte> kurt> but the estimation will be totally wrong.
> levitte> levitte> kurt> 
> levitte> levitte> kurt> Passing the hashed data to the drbg as entropy input is fine if
> levitte> levitte> kurt> you already know how much entropy that it contains.
> levitte> levitte> 
> levitte> levitte> Thanks, that's what I suspected.  Ok, on to the next step
> levitte> 
> levitte> Not done running, but does show some promise...
> levitte> 
> levitte>     : ; ./a.out ../../../levitte/vms-experiments/entropy-gathering/entropy-stats.bin  8 -v
> levitte>     Opening file: ../../../levitte/vms-experiments/entropy-gathering/entropy-stats.bin
> levitte>     
> levitte>     Running non-IID tests...
> levitte>     
> levitte>     Entropic statistic estimates:
> levitte>     Most Common Value Estimate = 0.975224
> levitte>     Collision Test Estimate = 0.902997
> levitte>     Markov Test Estimate = 0.410808
> levitte>     Compression Test Estimate = 0.811274
> levitte> 
> levitte> I assume that estimate is per "word" (i.e. per 8 bits of data in this
> levitte> case).
> 
> Ok, done running...  suffice to say, the first tests left me ever so
> hopeful...
> 
>    : ; ./a.out ../../../levitte/vms-experiments/entropy-gathering/entropy-stats.bin  8 -v
>    Opening file: ../../../levitte/vms-experiments/entropy-gathering/entropy-stats.bin
> 
>    Running non-IID tests...
> 
>    Entropic statistic estimates:
>    Most Common Value Estimate = 0.975224
>    Collision Test Estimate = 0.902997
>    Markov Test Estimate = 0.410808
>    Compression Test Estimate = 0.811274
>    t-Tuple Test Estimate = 0.0818796
>    Longest Reapeated Substring Test Estimate = 0.0818772
> 
>    Predictor estimates:
>    Multi Most Common in Window (MultiMCW) Test: 100% complete
>    	Correct: 507351
>    	P_avg (global): 0.508671
>    	P_run (local): 0.587891
>    Multi Most Common in Window (Multi MCW) Test = 0.76638
>    Lag Test: 100% complete
>    	Correct: 269907
>    	P_avg (global): 0.271051
>    	P_run (local): 0.347168
>    Lag Prediction Test = 1.52629
>    MultiMMC Test: 100% complete
>    	Correct: 11700
>    	P_avg (global): 0.011977
>    	P_run (local): 0.444824
>    Multi Markov Model with Counting (MultiMMC) Prediction Test = 1.16869
>    LZ78Y Test: 99% complete
>    	Correct: 572107
>    	P_avg (global): 0.573391
>    	P_run (local): 0.615723
>    LZ78Y Prediction Test = 0.699647
>    Min Entropy: 0.0818772
> 
> So I'd like to have it confirmed that I'm reading this right, that's
> about 0.08 entropy bits per 8 data bits?  Or is it per data bit?
> Depending on the interpretation, we either have 1 bit of entropy per
> 12 data bits...  or per 100 data bits...  The latter has my heart
> sinking...
> 
> -- 
> Richard Levitte         levitte at openssl.org
> OpenSSL Project         http://www.openssl.org/~levitte/
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