On Thu, 18 Mar 2021 19:06:07 -0700, Ed Jaffe wrote: >> >> Using clock values as a source of entropy is discouraged. If a >> (fe)malefactor can make a good guess at an interval during which >> the clock is sampled there's little entropy available. > >IBM Z was recently enhanced with a true random source in CPACF. > Has IBM published the technology, perhaps in a Redbook? A quick scan of https://www.ibm.com/downloads/cas/2MKRAY3Y is uninformative. Little more at: https://www.ibm.com/support/knowledgecenter/SSB23S_1.1.0.2020/gtps7/hwrandomnum.html
The latter suggests that a pseudo RNG is periodically reseeded by the TRNG >For all the many decades before that, all "random" numbers on the >mainframe were actually pseudo-random... > I'm imagining a beam splitter and a pair of detectors. Ah!: https://dl.acm.org/doi/10.1147/JRD.2013.2279599 -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
