[cryptography] Radiation Emission Controls

Jonathan Thornburg jthorn at astro.indiana.edu
Tue Jul 30 12:34:48 EDT 2013

On Tue, 30 Jul 2013, John Young wrote:
> An engineer formerly working at the National Radio Astronomy
> Observatory (http://www.gb.nrao.edu/nrqz/) lists its radiation
> emissions controls:
> http://cryptome.org/2013/07/radiated-emissions-control.htm
> Among them is the banning of vehicles which use spark plugs,
> thus diesel-fueled are required.
> Which suggests a question about radiation emissions at
> NSA Utah Data Center's 32 large generators.
> Since nearly all government and commercial data centers
> have generator back-ups, how are emissions from generators
> controlled?

This is confusing two somewhat different things:
Radio noise emitted by spark plugs is way too small to bother 99% of
other electronic equipment (including other computing equipment).  And
I don't think the NSA is worried about secret information being leaked
out via spark-plug radio emissions because the generator doesn't have
access to any secrets.  (I.e., the only information leaked would be that
the generator is running & its RPM (& maybe concievably the make/model
if inferrable from timing patterns), none of which seems particularly

In contrast, astronomers are looking for *very* tiny signals which
may well be drowned out by (e.g.) spark-plug noise, so
(a) radio telescopes use *very* sensitive low-noise radio receivers, and
(b) radio telescopes tend to be located in valleys so the terrain shields
    them from many human-made sources of radio noise,
(c) banning spark plugs (and electric razors and many other sources of
    low-level radio noise) near radio telescopes makes sense

> NRAO also "banned digital cameras down range after they
> proved quite noisy."
> Are noisy digital camera emissions more privacy threatening
> than phone signals? Is NSA harvesting those emissions?

It wouldn't surprise me if digital-camera CCD readouts radiated
radio signals just like (e.g.) flat-panel display screens, and that
the NSA could harvest these.  So... if someone takes a digital-camera
picture of secret information, a nearby radio receiver could pick up
enough signal to reconstruct the picture.

I'm sure the NSA tries to rule out leakage of this sort by the same
sort of anti-Tempest guidelines (e.g., radio shielding, trying to
enforce a no-spies-nearby "quarantine zone" around secure facilities)
as for other compromising radio emissions.  Not to mention that cameras
are often forbidden in secure facilities anyway.....
takes a digital-camera

-- "Jonathan Thornburg [remove -animal to reply]" <jthorn at astro.indiana-zebra.edu>
   Dept of Astronomy & IUCSS, Indiana University, Bloomington, Indiana, USA
   on sabbatical in Canada through late August 2013
   "There was of course no way of knowing whether you were being watched
    at any given moment.  How often, or on what system, the Thought Police
    plugged in on any individual wire was guesswork.  It was even conceivable
    that they watched everybody all the time."  -- George Orwell, "1984"

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