On Fri, Mar 07, 2003 at 02:38:56PM -0500, Tyler Durden wrote:
>
> Undersea, I've heard that NSA uses splices, and that NSA has its own sub
> for that purpose. (And the company I used to work for did some work on
> undersea NSA optical projects, so I tend to believe the rumors I heard
> there.)
Tapping the cable isn't all that impossibly hard (though the
things carry considerable HV to power the repeaters/optical amplifiers
so it isn't entirely trivial either).
But getting the bits from under the ocean somewhere back to
Fort Meade without being detected must be more interesting.
One wonders if there is any other practical technology than
just stringing another cable covertly all the way back to the nearest
friendly location where intercept gear and links back to the US can be
set up. Are there bouys out there in the middle of the ocean with
satellite dishes or laser optical transmitters on them ? How do we hide
them ? It probably is true that the right wavelength laser will
penatrate water for some limited distance so a link could be set up from
a bouy near but below the surface to a sensitive telescope in earth
orbit. But this sounds awfully risky and complex.
And I guess a simpler approach might be to fly aircraft or
drones over the tap and relay that way, though having aircraft
circling somewhere over a cable would be a dead giveway I should
think...
The original IVY BELLS tap was of a limited capacity FDM analog
coax link and was done by inductively sensing minute skin currents
flowing on the surface of the cable (eg leakage of the signal). AFAIK
there was only one coax in each direction so separating out traffic was
done by demultiplexing the FDM-SSB signals (same way it was done on
shore) as there was no overlap of traffic on multiple wires.
Apparently the IVY BELLS taps involved recording certain voice
channels on vast capacity tape recorders powered by Plutonium decay
theroelectric generators. The tapes were only rescued months later
when the sub came back to the tap site.
Doing this for a sonet ring carrying 10 gbs or so as some
undersea cables now do seems rather challenging - at the very least
how one would follow changes in channel allocations and traffic loading
would seem very problematic. And intercepts that are weeks or months
old would be very much less interesting in most cases than near real
time intercepts - particularly of targets like terrorists.
--
Dave Emery N1PRE, [EMAIL PROTECTED] DIE Consulting, Weston, Mass.
PGP fingerprint = 2047/4D7B08D1 DE 6E E1 CC 1F 1D 96 E2 5D 27 BD B0 24 88 C3 18
