Stories
Slash Boxes
Comments

SoylentNews is people

posted by janrinok on Saturday April 20 2019, @11:10AM   Printer-friendly
from the schschschschschschschsch dept.

Famed hardware hacker Bunnie Huang has posted an overview of his notes on designing an open source entropy generator. His summary links to the full notes which include schematics, measurement results, as well as other key details.

The final optimized design takes <1cm2 area and draws 520uA at 3.3V when active and 12uA in standby (mostly 1.8V LDO leakage for the output stage, included in the measurement but normally provided by the system), and it passes preliminary functional tests from 2.8-4.4V and 0-80C. The output levels target a 0-1V swing, meant to be sampled using an on-chip ADC from a companion MCU, but one could add a comparator and turn it into a digital-compatible bitstream I suppose. I opted to use an actual diode instead of a NPN B-E junction, because the noise quality is empirically better and anecdotes on the Internet claim the NPN B-E junctions fail over time when operated as noise sources. I'll probably go through another iteration of tweaking before final integration, but afaik this is the smallest, lowest power open-source avalanche noise generator to date (slightly smaller than this one [PDF]).


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 0) by Anonymous Coward on Saturday April 20 2019, @06:10PM

    by Anonymous Coward on Saturday April 20 2019, @06:10PM (#832650)

    thanks for both links guys!

    't was a trick question.. but hey, didn't know about that one could fuzz prngs to increase entropy -- which, now that i've written it that may makes sense of course.

    to the other person wondering about shaped randomness; random is an absolute like infinity (at least in my mind).
      if you need it to have a shape, you filter it, which means you mult it the curve you want it to conform to.