News for hackers. Stuff that matters.

A comment on Apple's T2 chip will prevent hackers from eavesdropping on your microphone. Parent comment

Re:Apple's T2 chip will prevent hackers from eavesdropping o... by bigiain on Sunday November 04, 2018 @05:36PM (#18378427)
There's at least a pre amp and a d/a converter that the mic needs to have powered up and running before any of it's signal can be used by the rest of the computer.
[ Parent | on HN ]
Re:Apple's T2 chip will prevent hackers from eavesdropping o... by newnewpdro on Sunday November 04, 2018 @05:46PM (#18378470)
Which will all be inside an IC, away from the microphone.

So what, does the light turn on whenever the entire IC sees power? Because if it relies on a signal from within the software-controlled IC, that's not exactly trivial to audit.

[ Parent | on HN ]
Re:Apple's T2 chip will prevent hackers from eavesdropping o... by XMPPwocky on Sunday November 04, 2018 @06:16PM (#18378584)
The trivial solution would be a LED + resistor just wired across the mic's power rails.
[ Parent | on HN ]
Re:Apple's T2 chip will prevent hackers from eavesdropping o... by newnewpdro on Sunday November 04, 2018 @07:13PM (#18378829)
When the microphone is a passive connected to a multifunction IC there's no such power rail.
[ Parent | on HN ]
Re:Apple's T2 chip will prevent hackers from eavesdropping o... by justtopost on Sunday November 04, 2018 @09:10PM (#18379340)
Most laptop mics are condenser electret mics which usually use a small dc current, although not always.
[ Parent | on HN ]
Re:Apple's T2 chip will prevent hackers from eavesdropping o... by newnewpdro on Monday November 05, 2018 @12:07AM (#18380008)
Not the last time I went down this road hardening a Thinkpad, see Step 6 at [1] (not my site). I haven't bothered with any smartphones yet, so I can't speak to what they tend to use for a mic. But if I carried one I'd definitely rip out all the voice coils and rely on a pair of headphones w/integrated mic for voice comms to mitigate potential for eavesdropping.

[1] https://blog.patternsinthevoid.net/replacing-a-thinkpad-x60-...

[ Parent | on HN ]
Re:Apple's T2 chip will prevent hackers from eavesdropping o... by colejohnson66 on Monday November 05, 2018 @07:31AM (#18381772)
When replacing the lightning assembly on my iPhone 6, I noticed that the microphone looks passive. Here’s a photo[0]; It’s the little bronze(?) square next to the headphone jack.

[0]: https://www.ifixit.com/Store/iPhone/iPhone-6-Lightning-Conne...

[ Parent | on HN ]