> > Russell Leidich (at Friday, May 6, 2016, 10:16:12 PM): >> Most of the entropy in a system is manifest in terms of the clock >> skew between direct memory access (DMA) transfers from external >> devices and the CPU core clocks, which unfortunately does not >> traverse the kernel in any directly observable manner. > > someone please confirm this, because i'm not a linux expert, but i > don't believe user space code can do dma without the kernel knowing > about it. > > also, i assert that such clock drifts provide much less entropy than > you make it look like. > The premise is generally wrong these days. Well designed entropy sources on silicon generate between 200Mbits/s and 5Gbits/s per source. I think most vendors are getting in on the act. We have been pretty open with our ES designs and I've seen very smart ES papers. I particularly like Samsung's ring of rings for a process agnostic circuit.
> >> interrupt timing, unless we extend the definition of "interrupt" to >> include quasiperiodic memory accesses from external clients. > > again, i'm no exert in low level kernel stuff, but to my knowledge, > everything happens through interrupts, even dma uses it to report the > end of an operation. > > > _______________________________________________ > cryptography mailing list > [email protected] > http://lists.randombit.net/mailman/listinfo/cryptography > _______________________________________________ cryptography mailing list [email protected] http://lists.randombit.net/mailman/listinfo/cryptography
