Deafening the Bug

I know a lot of people who put a piece of tape over their computer’s webcam. While this is a sane countermeasure, I’m honestly less worried about my webcam than the microphone built into my laptop. Most laptops, unfortunately, lack a hardware disconnect for the microphone and placing a piece of tap over the microphone input often isn’t enough to prevent it from picking up sound in whatever room it’s located. Fortunately, Apple has been stepping up its security game and now offers a solution to the microphone problem:

Little was known about the chip until today. According to its newest published security guide, the chip comes with a hardware microphone disconnect feature that physically cuts the device’s microphone from the rest of the hardware whenever the lid is closed.

“This disconnect is implemented in hardware alone, and therefore prevents any software, even with root or kernel privileges in macOS, and even the software on the T2 chip, from engaging the microphone when the lid is closed,” said the support guide.

The camera isn’t disconnected, however, because its “field of view is completely obstructed with the lid closed.”

While I have misgivings with Apple’s recent design and business decisions, I still give the company credit for pushing hardware security forward.

Implementing a hardware cutoff for the microphone doesn’t require something like Apple’s T2 chip. Any vendor could put a hardware disconnect switch on their computer that would accomplish the same thing. Almost none of them do though, even if they include hardware cutoffs for other peripherals (my ThinkPad, for example, has a build in cover for the webcam, which is quite nice). I hope Apple’s example encourages more vendors to implement some kind of microphone cutoff switch because being able to listen to conversations generally allows gathering more incriminating evidence that merely being able to look at whatever is in front of a laptop.