re tempest in article apr infodev cam ac uk rja cl cam ac uk ross anderson writes res colnet cmhnet org rob stampfli writes wouldn t a a second monitor of similar type scrolling gibberish and adjacent to the one being used provide reasonable resistance to tempest attacks we ve got a tempest receiver in the lab here and there s no difficulty in picking up individual monitors their engineering tolerances are slack enough that they tend to radiate on different frequencies even where they overlap you can discriminate because they have different line synch frequencies you can lock in on one and average the others out the signals are weird in any case with varying polarisations and all sorts of interactions with the building just moving a folded dipole around is also highly effective as a randomised means of switching from one monitor to another hell just set up a spark jammer or some other very electrically noisy device or build an active farrady cage around the room with a noise signal piped into it while these measures will not totally mask the emissions of your equipment they will provide sufficient interference to make remote monitoring a chancy proposition at best there is of course the consideration that these measures may and almost cretainly will cause a certain amount of interference in your own systems it s a matter of balancing security versus convenience btw i m an ex air force telecommunications systems control supervisor and telecommunications cryptographic equipment technician remember waco who will the government decide to murder next maybe you opinions are mine i don t care if you blame the university or the state
