Kurt, > -----Original Message----- > From: openssl-dev [mailto:openssl-dev-boun...@openssl.org] On Behalf Of > Kurt Roeckx > Sent: 30 July 2016 12:19 AM > To: openssl-dev@openssl.org > Subject: Re: [openssl-dev] DRBG entropy
> Have you tried running NIST's software > (https://github.com/usnistgov/SP800-90B_EntropyAssessment) > yourself? Can you run it in verbose mode and give the results of all the > tests it ran? Yes, this is the test that indicated an entropy of 2b/B. I ran the test on 1M and 4M and the result was 2.19 and 2.35 respectively. The 4MB file test output is appended below. Now in the OpenSSL UG2.0 section 6.1.1 a paragraph states: "Now suppose we have a low grade entropy source which provides just 1 bit of entropy per byte. Again assume it is uniform (e.g. we don't get 8 bits of entropy in byte 1 and nothing in the next 7). Again let's have a block size of 16 bytes. This time to get 256 bits of entropy the source must provide it in a 256 byte buffer. An extra block is required which makes 272 bytes but because we only have 1 bit of entropy per byte it just needs to supply 272 bits of entropy." Am I correct to state that for a tested entropy source of 2b/B and the same assumptions as in the paragraph, I need to return 8 blocks of 16B each in my get_entropy() callback? Thanks LJB ****************************************************** Read in file randomness.bin, 4194304 bytes long. Dataset: 4194304 8-bit symbols, 256 symbols in alphabet. Output symbol values: min = 0, max = 255 Running entropic statistic estimates: - Most Common Value Estimate: p(max) = 0.00411016, min-entropy = 7.92659 - Collision Estimate: p(max) = 0.00873199, min-entropy = 6.83947 - Markov Estimate (map 6 bits): p(max) = 9.71537e-228, min-entropy = 5.89156 - Compression Estimate: p(max) = 0.00743246, min-entropy = 7.07194 - t-Tuple Estimate: p(max) = 0.00495551, min-entropy = 7.65675 - LRS Estimate: p(max) = 0.155747, min-entropy = 2.68272 Running predictor estimates: Computing MultiMCW Prediction Estimate: 99 percent complete Pglobal: 0.003997 Plocal: 0.001358 MultiMCW Prediction Estimate: p(max) = 0.00399729, min-entropy = 7.96676 Computing Lag Prediction Estimate: 99 percent complete Pglobal: 0.004009 Plocal: 0.001358 Lag Prediction Estimate: p(max) = 0.00400879, min-entropy = 7.96262 Computing MultiMMC Prediction Estimate: 99 percent complete Pglobal: 0.004934 Plocal: 0.195448 MultiMMC Prediction Estimate: p(max) = 0.195448, min-entropy = 2.35514 Computing LZ78Y Prediction Estimate: 99 percent complete Pglobal: 0.004034 Plocal: 0.195448 LZ78Y Prediction Estimate: p(max) = 0.195448, min-entropy = 2.35514 ----------------------- min-entropy = 2.35514 -- openssl-dev mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-dev
