[Cryptography] jammers, nor not

[Michael Marking]

On Tue, Feb 28, 2017 at 11:15:35AM -0800, Julian Macassey wrote:
>[...]
> 	What was also interesting was the electrical power to the
> building. There was an outbuilding that was set up with a local
> sub-station privately owned - No not by Southern California
> Edison but Lockheed, although SCE supplied the high voltage to
> Lockheed. The output of the sub-station power drove large
> electric motors. The electric motors drove generators that
> supplied the super secret building with power so providing an
> "air gap".
> 
> 	All this to make sure the Soviets wouldn't know what was
> going on.

I wouldn't be surprised if we spent more time and energy keeping
secrets from the American people, than we spend on keeping them
from the Russians.

WRT the generators, on some aircraft the generator in the cage is
powered by (non-conducting) hydraulic fluid pumped in from the
outside. In those cases, however, the main purpose of caging the
electronics is for EMP shielding, some types of which have
similarities to the shielding used to prevent escaping signals. In
both cases, when cages are used, one goal is to attenuate the
currents induced in the inner (or outer) layers (depending on which
direction you're going). It is possible that another goal of the
shielding in the Lockheed building was protection against EMP.
(Maybe "flight simulator" was a cover story.)

I was once working inside a Faraday cage used for qualifying and
for testing avionics. This was not the kind of cage a naive
engineer without experience would construct. Nevertheless, inside,
the spectrograph showed distinct peaks from outside AM and FM radio
and broadcast TV stations. It's hard and expensive to construct a
good cage. There exist "active" cages, raising the bar still higher.

Even black holes leak Hawking radiation.

For that reason, although I realize that the suggestions about
aluminum foil are tongue-in-cheek -- although someone might sell
cheap solutions to a gullible public (an opportunity!) -- a serious
military-grade solution isn't going to be trivial or low in cost.
The equipment to test and to verify a solution is, by itself, a
major budget item.