Via Bruce Schneier, here’s a piece about how a graduate student has reinvented – and hence blown the lid off of – a technology that can “transmit data at high rates through thick, solid steel or other barriers”. It can carry power, too.
Why is this a big deal? Well, not only is it a reinvention of something that BAE had built for the British government for purposes undisclosed, but it’s a technology that can cut through Faraday cages and eavesdrop on electronic communications that are supposed to be heavily shielded from the world outside:
If you had the through-metal technology now reinvented by Lawry, however, your intruder – inside mole or cleaner or pizza delivery, whatever – could stick an unobtrusive device to a suitable bit of structure inside the Faraday cage of shielding where it would be unlikely to be found. A surveillance team outside the cage could stick the other half of the kit to the same piece of metal (perhaps a structural I-beam, for instance, or the hull of a ship) and they would then have an electronic ear inside the opposition’s unbreachable Faraday citadel, one which would need no battery changes and could potentially stay in operation for years.
So Tristan Lawry has unwittingly levelled the espionage-tech playing field. It’s hard to hide secrets about hiding secrets.
It is worth repeating that this scheme will only work if the perpetrator can succeed in installing a surreptitious, powered, ultrasonic transducer on the *inside* of the otherwise “secure” shielded enclosure. A properly-shielded facility that has not been penetrated or otherwise compromised by such an intruder is still safe. People, as always, remain the weakest link in security. Good security people know that any time you let untrusted personnel inside (or even very near) such a shielded facility, you are taking risks.