[cryptome] how embassy eavesdropping works

  • From: Eugen Leitl <eugen@xxxxxxxxx>
  • To: cryptome@xxxxxxxxxxxxx
  • Date: Mon, 28 Oct 2013 14:52:45 +0100

Some more gory details, several images.


How embassy eavesdropping works

Inside the interception galleries at GCHQ’s former Irish monitoring tower.
The brown area of the wall is made from a special dielectric (insulating)
panel – allowing radio waves to pass through and be intercepted, while
blocking visible light and concealing the interception antennae behind (since
removed).   Inset: Duncan shows where the antennae were sited.

Secret US espionage activity against Germany, from Germany and  revealed this
week by Der Spiegel has added new evidence to European concerns about the
interception of the phones of the Germany's Chancellor Merkel and other world
leaders.    Duncan was a consultant to Der Spiegel for the enquiry and
identified the listening "windows" shown on the front cover.

Similar, top secret listening installations, protected from scrutiny by
diplomatic immunity are used to conduct massive electronic listening, usually
from the top floors of US embassies.  One is in Berlin.  Others are located
in European capitals from Stockholm to Athens..

Duncan filmed inside a similar decommissioned British surveillance facility
using the same techniques as the US and UK currently use to spy in Europe's
capital cities.

His investigations led to a 1999 television expose about how the UK had
secretly intercepted and analysed all the international communications of the
Irish Republic, an EU member.  GCHQ's activities were later found to be
unlawful by the European Court of Human Rights.

You can read more about embassy surveillance here
How embassy eavesdropping works

The key visible feature of most embassy and diplomatic sites that give away
their secret spying missions are large windowless areas on top floors, and
also sheds or hangers on the roof which are designed to look as though they
might contain lift or air conditioning apparatus. 

At the US Embassy in Berlin, the lighter coloured panels on the south west,
north west and northeast corners of the rooftop surveillance facility are
dielectric "radio windows" which allow all types of radio signals to reach
collection and analysis equipment on the roof and floor directly below.

The "radio window" panels are made of special material which does not conduct
electricity.   That is so weak radio signals coming in from all corners of
the city are not diminished (attenuated) as they pass into the building and
reach the sigint (signals intelligence) antennae.

Usually, dielectric window panels for signals intelligence work are made of
plastic or fibreglass.   They are often shaped and coloured to look as though
they are a normal part of the building, or are special architectural

External Close up of Radio window panel at Capenhuirst

External Close up of Radio window panel at Capenhurst

Hidden behind the panels are a range of special monitoring antenna, dishes or
arrays which collect every type of commercial and civil mobile, and
government communications, including internet traffic, on all available

Rooftop "sheds" like in Berlin can be seen on dozens of US embassies in
Europe and around the world, except in "Five Eyes" allied countries such as
the UK.  Apart from the "collection" sheds, large processing areas are needed
to analyse and transmit the result of interception to the global surveillance

Windowless top floors, such on the south wing of the Berlin embassy provide
"SCIFs" - Secure Compartmented Intelligence Facilities - which are needed to
prevent any radio signals from the interception and analysis equipment
themselves leaking out.    The processing operators and equipment for the
"Special Collection Service" are sited in these rooms.

The largest and most obvious US diplomatic surveillance facility in Europe is
on the roof of the Geneva consulate, overlooking the United Nations.    The
Berlin eavesdropping facility is one of the largest, comparable in size to
those in sensitive Middle East locations such as Yemen or Cyprus. 

When the former GCHQ surveillance installation in Capenhurst in northern
England was retired from service and put up for sale (TV link), it was
possible to inspect inside and see what the embassy surveillance centre might
look like.

The 150 ft (50 metre) tower had been placed directly between two British
Telecom microwave radio towers carrying telephone traffic. It was the ideal
place to discreetly intercept international telephone calls of the Irish
government, businessmen and also those of suspected of involvement with IRA

The hi-tech tower included eight floors of advanced electronic equipment and
three floors of aerial galleries.  These were used to extract and sort the
thousands of communications passing through every hour.

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