Am Freitag, 29. November 2013, 11:31:49 schrieb Joachim Strömbergson: Hi Joachim,
> Aloha! > > Stephan Mueller wrote: > > The problem is that dieharder & Co only show the statistical quality. > > > > Based on my real-world attempts to the CPU jitter issue used as a > > > > noise source for /dev/random, the questions around the entropy of the > > data still remains -- see the email threat on LKML. > > (I feel I need to read up on the LKLM discussion). > > Yes, but when having access to an entropy source - what other ways > besides statistical tool such as Dieharder do we have to measure the > quality of the entropy? Provide a rationale why: - your observed noise source is really random - explain the uncertainty in the noise source > > The problem as I have understood it is that we don't have direct access > to the entropy source in Bull Mountain. And that we have to trust Intel > on telling us the truth, that there actually is a nice entropy source, > not simply a CSPRNG with a seed known by certain organizations. The lack > of openness, transparency and control of the entropy source is what is > missing. You are right. But when introducing a noise source that is not commonly understood, you have to make some explainig. > > Or am I missing something? > > > That is why my current patch set only uses the jitter noise source as > > last resort, i.e. when /dev/random is about to block. As long as the > > other noise sources produce entropy, my jitter noise source is not > > even asked. > > > > With that approach, however, /dev/random will never block any more on > > any system. > > That is actually pretty neat. > > What bitrate do you get from your RNG? On an Intel 2nd gen i7 I get about 15kBytes/s. On an embedded MIPS (my Internet router), I get still 1kB/s. > > BTW: Just downloaded your PDF and OMG it is really big. I think I have > my weekend reading identified. ;-) Do not be scared. about 75% is only in numbers and graphs of the 200+ systems I tested in appendix F. The rest is pretty small. :-) > > BTW2: You should probably reference jytter in your paper, it would be > very interesting to see the comparison between them. I will first have to make myself familiar with this one. Ciao Stephan -- | Cui bono? | _______________________________________________ cryptography mailing list cryptography@randombit.net http://lists.randombit.net/mailman/listinfo/cryptography
