[cryptography] Radiation Emission Controls

[David I. Emery]

On Wed, Jul 31, 2013 at 04:23:15PM +0200, Eugen Leitl wrote:
> On Tue, Jul 30, 2013 at 03:18:51PM -0400, Riad S. Wahby wrote:
> 
> Is there any RF sigint at all done at the Utah site? It could
> all well be just a big crunch and storage facility. It would
> help if we had a good fiber map of the general area.

	Guys, there isn't much of interest to listen to in Utah... even
for NSA. Ground based RF sigint is either very local - directed at
things like foreign cellphone networks or other short range
VHF/UHF/Microwave comms systems that are only receivable a perhaps a few
thousand feet to a small number of miles away or aimed at satellites or
LF/MF/HF radio transmissions.   There are only so many satellites and we
have most of those of interest covered by dishes somewhere else
already...  and HF radio carries very little these days and optimum
sites for receiving those signals are also already in place.

	If there is much of any RF at the facility it will likely be
satellite links bringing in material of interest and maybe communicating
with remote surveillance vehicles to receive their take and control
their operation ... but many of the relevant satellites are not visible
from Utah.   And ground operations centers for those vehicles are mostly
elsewhere too...

	By a great many many orders of magnitude the NSA take from
tapping fiber world wide dwarfs almost all traditional radio reception
except maybe collection of cellphone signals from platforms that
perforce have to be more or less line of sight from the cellphone of
interest (and therefore not in Utah).

	Most radio propagation is line of sight.   Quite hard for a
ground based facility to receive much from other ground based
transmitters for more than a relatively few miles (easily less than
around 100).

> I suspect that the NSA is doing a lot of decentral signal
> prefiltering and processing at the network edge, and only uses 
> large central facilities if they're unavoidable.

	They HAVE to limit the edge take and filter, too much to deal
with otherwise.

-- 
  Dave Emery N1PRE/AE, die@dieconsulting.com  DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."