It’s the ultimate privacy nightmare: hackers taking over your machine and subverting the microphone to extend their reach beyond the digital confines of the operating system into the real world. That’s a scenario that Microsoft hopes to take off the table with a newly patented design that implements privacy measures directly into the hardware.
The proposed microphone comes embedded in an integrated circuit with a built-in feature extraction chip that is preconfigured for a specific function like detecting a particular voice command or recording conversations without registering any semantical patterns that can be used to identify the speaker. Since everything else is discarded, the filing suggests future implementations will likely include multiple such processors and let you switch between them for different applications.
That may seem like a very roundabout way to accomplish what can be achieved programmability with only a single slightly more sophisticated processor, but serves an important purpose. The limited nature of the feature extraction circuitry not only prevents applications from modifying its function but also hackers who might abuse that adaptability to their own malicious ends.
Even if a committed attacker did somehow find a way to change the instructions encoded into the chip, though, they’d still need physical access to perform the necessary modifications, which Microsoft’s engineers have considered as well. The feature extractor is embedded inside the board containing the microphone in a way that the filing indicates makes removal impossible without damaging the silicon.
Of course, all of that doesn’t account for the possibility of someone sneaking into your home and replacing your microphone with an identical-looking unit crafted in some clandestine lab to eavesdrop on private conversations without raising any suspicious. But unless you find yourself caught up in a real-life spy drama, that won’t happen, and Microsoft’s invention will block practically all forms of snooping.
That includes webcam spying, too. After all, there’s no reason why integrated feature extraction couldn’t be used with cameras, or any other sensor for that matter. The patent filing states as much, suggesting that Microsoft is keenly aware of the potential business opportunity in selling privacy-hardened computer accessories.