[Cryptography] Radioactive random numbers

Perry E. Metzger perry at piermont.com
Wed Sep 11 19:18:51 EDT 2013

On Thu, 12 Sep 2013 08:47:16 +1000 (EST) Dave Horsfall
<dave at horsfall.org> wrote:
> Another whacky idea...
> Given that there is One True Source of randomness to wit
> radioactive emission, has anyone considered playing with old smoke
> detectors?

People have experimented with all sorts of stuff, and you can make
any of hundreds of methods from cameras+lava lamp+hash function to
sound cards to radioactive sources work if you have budget and time.

The issue is not finding ways to generate entropy. The issue is that
you need something that's cheap and ubiquitous.

User endpoints like cell phones have users to help them generate
entropy, but the world's routers, servers, etc. do not have good
sources, especially at first boot time, and for customer NAT boxes and
the like the price points are vicious.

The attraction of methods that use nothing but a handful of
transistors is that they can be fabricated on chip and thus have
nearly zero marginal cost. The huge disadvantage is that if your
opponent can convince chip manufacturers to introduce small changes
into their design, you're in trouble.

Perry E. Metzger		perry at piermont.com

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