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 -- All mistakes in this message belong to me - you should not use them!