Re: Tempest Info

[Lyal Collins <lyalc@ozemail.com.au>]

Julian Assange wrote:
> 
> >
> > Bill Stewart writes:
> > >  Also, of course, your electrical power system needs to be
> > >  shielded and filtered, so only 60Hz gets through, unless you
> > >  plan to stick to laptops and bring in spare battery packs.
> >
> > At HoHoCon a few years ago, someone did a tempest demo and mentioned that
> > signals could be recovered from water pipes!  Fire sprinkler systems were
> > specifically mentioned...
> 
> Water pipes are often form the earth line. If only 60hz (US) can get through
> the power cables then only 60 hz can get into the water pipes (I'll ignore
> re-radiating, because water pipes are the least of your problems there).

As the water pipe can form a signal "drain", monitoring that with respoect to an 
artificial refernce "earth" allowsthe signal(s) to be reccovered, unless the waterpipe is of very low 
impedance.
lyal

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