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Who controls the switch? You need an entire secure system distinct from the untrusted CPU - or a manual switch on the side. The latter goes against everything
by slededit 8y ago
Who controls the switch? You need an entire secure system distinct from the untrusted CPU - or a manual switch on the side. The latter goes against everything Apple believes in design wise.
- davnicwil 8y agoI'm suggesting the lid could control the switch, physically, as in when you close it the mic's circuit is broken.
- slededit 8y agoYea that could work. I think this is cheaper for them surprisingly enough. Switches are expensive.
- 542458 8y agoExpensive and failure-prone!
- lstodd 8y agoJust put a magnet-actuated switch into the mic itself and a magnet in the corresponding place in the body - problem solved. Nothing to break, zero attack surface, what's not to like?
- kondro 8y agoExcept the magnet-actuated switch for each mic.
- lstodd 8y agoThose are rated for over hundreds of millions of switching cycles. They would be the last thing that breaks in a laptop. But if you're so against moving parts, a hall sensor and a transistor would achieve the same result.
- dpkonofa 8y agoOr, you know, they could use a chip that they're already putting into the device (like the T2) and not have to use additional components. Same end result without the extra parts.
- lstodd 8y agoAnd an unknown and unknowable attack surface. At least with the switch if the mic doesn't work you just check for magnets around it and that's it.
- xvector 8y agoI'd argue the T2 chip is actually more secure than your method. Magnets can be removed. The T2 chip cannot. Not without rendering the computer unusable and the data irrecoverable. The chip provides a hardware disconnect for the microphone, just like your idea. Except it's baked into the silicon instead of an additional large part in the body of the computer. Regardless, if your attack model is "T2 chip is compromised", all bets are off. Worrying about the microphone would be the absolute least of your concerns. All your local and iCloud data can now be decrypted, your 2FA is compromised, so on and so forth. The T2 chip and Secure Enclave provide the strongest security guarantees in today's computers and mobile devices respectively. I'm not worried about a compromise of the T2 chip, to be honest.
- Johnny555 8y agoI'd argue the T2 chip is actually more secure than your method. Magnets can be removed. The T2 chip cannot. Not without rendering the computer unusable and the data irrecoverable If someone can physically modify your laptop, you've already been hacked, T2 chip or not. if your attack model is "T2 chip is compromised" I think the more realistic attack model is "Apple enables the undocumented 'turn on mic while closed' feature that it was required to add through a national security letter that they can't talk about." And then that secret hack is either discovered (or stolen) by other government.
- shawnz 8y agoWhy would that be more likely to fail than the lid-closed sensor which they are currently using for this application?
- lstodd 8y agoThe lid sensor likely won't fail. What will likely fail is this T2 chip and/or its firmware. And it will fail in mysterious and unfixable ways.
- JumpCrisscross 8y ago> the lid could control the switch Doing it on a chip sounds more reliable than adding a moving part.
- sjwright 8y agoAnd sounds more scalable too, if they wanted to start applying the same principle to other components like accelerometers, light sensors etc. The point (it seems) of the T2 chip is that it's isolated from the main system and has far fewer opportunities for exploitation, while leveraging efforts already expended for the iPhone. In my mind the eventual goal of the T1 / T2 etc chip line will be to do everything for a Mac that an iPhone does—storage, webcam control and encoding, audio in/out, fingerprint reader, sensors, battery monitoring, power management etc—and then expose it all to the main system en masse.
- Johnny555 8y agoAnd sounds more scalable too, if they wanted to start applying the same principle to other components like accelerometers, light sensors etc. Is it easier the "turn off" signal from the T2 chip to each device to be turned off than it is to route the "turn off" signal from the lid closed switch/sensor to each device. Why does it have to pass through the T2 chip first?
- MBCook 8y agoBut that would mean you can’t use the built-in microphone when actively using the computer in clamshell mode.
- anticensor 8y ago[sarcasm="true"]bit-bangs the lid servo [/sarcasm]
- imran3740 8y agoWhat about a physical killswitch goes against Apple's design? The iPhone has always had a ringer/vibrate switch on its side since it was introduced. Obviously it doesn't do anything hardware-wise, but it's still a switch that disables some functionality.
- deleted 8y ago[deleted]
- slededit 8y agoThat has a common use case of not wanting your phone ringing in a meeting. People expect their computers not to listen to them when not actively using the mic. Your switch is the program that records you, a second is redundant and confusing.
- IBM 8y agoAlmost all of Apple's security features are invisible and by default and don't get in the way. They're striking the balance between user experience and security.
- Spooky23 8y agoIt’s a part that when it fails is probably a motherboard replacement ($), and it fails often because people.
- deleted 8y ago[deleted]