6 ms·

From my understanding, Apple has done sort of what you're asking for, they've hooked up the physical wiring of the camera LED to the camera itself, so it is phy

by atonse 7y ago

From my understanding, Apple has done sort of what you're asking for, they've hooked up the physical wiring of the camera LED to the camera itself, so it is physically impossible to power the camera without the LED being turned on (as opposed to the "turn on LED" being part of firmware logic that could be hacked).

jonny_eh 7y ago
What about the mic?
t34543 7y ago
I’ve read this as well but my macbook senses ambient light and adjusts my backlight accordingly. Isn’t this through the camera - with no LED?
- Analemma_ 7y ago
  No, the ambient light sensing is done with a light sensor on the body - look for the tiny hole drilled into the chassis. It doesn't use the camera.
  - ljm 7y ago
    Remember when they did that for your battery power indicator! With a little button to trigger it.
- eightysixfour 7y ago
  https://apple.stackexchange.com/questions/347895/where-is-the-true-tone-ambient-light-sensor-on-the-2018-macbook-pro https://apple.stackexchange.com/questions/347895/where-is-th...
- klodolph 7y ago
  The ambient light sensor is right next to the camera, I think it's usually to the left. It's a bit hard to test since they're close together. Macs have had ambient light sensors for a long time. For example, take an old iMac and put it to sleep. The power light will pulse with a period of about 2s, and the brightness will depend on the ambient light level. Edit: Just tested on my MBP. Opened photo booth, covered the camera with my thumb, shone a bright flashlight at the point just left of the camera. The display got brighter but Photo Booth showed no changes in what the camera was seeing.
skybrian 7y ago
That's useful, but it's not as reassuring as a hardware switch where you can see it work. (For video, anyway. I don't see any similar solution for audio.)
- ehsankia 7y ago
  Two reasons why switch is better: 1. If it does happen to light up, what would you do, turn off your computer? That's shitty. 2. What if your AFK and aren't looking at the light?
  - toxik 7y ago
    Arguably better to be aware of the breach than prevent one sensor from leaking too.
  - ljm 7y ago
    A switch plus a notification (as opposed to modal prompt) if you try to get into video/audio calls but forget to flip it back. Just to remind you that you’re trying to enable video/mic but have the hardware switched off.
XCSme 7y ago
I remember there was a story saying that it's possible, via software only (due to a "bug" and some "poor" hardware design), to turn on the camera without activating the LED.
- Nextgrid 7y ago
  It used to be that the LED was controlled by firmware. As far as I know this is fixed now but I haven't proven it myself. There are leaked schematics of MacBooks online (that unofficial repair shops use) so if you want to investigate this I'd expect it to be a good place to start.
- css 7y ago
  https://jscholarship.library.jhu.edu/handle/1774.2/36569 https://jscholarship.library.jhu.edu/handle/1774.2/36569 (2013)
  - seandougall 7y ago
    Published in 2013, but describes "the Apple internal iSight webcam found in previous generation Apple products including the iMac G5 and early Intel-based iMacs, MacBooks, and MacBook Pros until roughly 2008".
SlowRobotAhead 7y ago
FWIW... I bet you could power the camera, get a still frame at 60fps, shut it down, and not see the led come on. It would be 1/60, 16ms plus or minus the amount of overhead needed, plus autofocus and exposure correction might make it impractical, but it’s definitely not a bulletproof fix.
- heavenlyblue 7y ago
  Apple could simply make the camera take 1 second to activate.
  - SlowRobotAhead 7y ago
    Slow spool up embedded devices... we’re moving backwards :)
    - heavenlyblue 7y ago
      If Google Calendar thinks it’s OK to set a 500ms animation on opacity for event edit dialog - then it doesn’t seem like a 1 sec spooling for a webcam is too much :)
- cstejerean 7y ago
  How much would you bet?
  - SlowRobotAhead 7y ago
    Considering I have a device here that has an I2C camera and in firmware I can turn it on and off at right around 25ms, I’d consider betting quite a bit. Instead of being snarky, how about you explain why this isn’t possible. Even if it was 100ms almost no one would catch that.
    - cstejerean 7y ago
      I’m not being snarky, and we’re not talking about some random device you have. We’re talking about the camera on a Mac. The bet is that you can’t turn it on and off so fast as to be un-noticeable because there is a noticeable delay between that light turning on and getting an image from that camera. So I’ll gladly take the other side of that bet.
Wowfunhappy 7y ago
This is a better solution overall, as it's "by default". A hardware switch relies on the user to be privacy conscious. An LED which is physically connected to the camera circuit (!) is immediately noticeable if it turns on unexpectedly.
- rxhernandez 7y ago
  As a layperson in this arena, I'm skeptical as to whether it's a great solution. Is it possible to turn the camera on and off very quickly? If so, a smart hacker could do that really quickly and if the owner ever notices they would probably think there is a problem with the electrical rather than thinking they are being monitored.
  - EGreg 7y ago
    It is just like the small hacks that are possible with ANY of these “require UNRELATED user interaction” things. Like being able to speak “” when the user clicks. Or something really short or kind of unpronounceable like “,,,,”. Apple could of course try to require the first speech to always be long enough to be unmistakably speech. But otherwise ANY user interaction is enough to enable ANY speech. The alternative would he to have dialogs for everything: “would you like to turn on the camera?” “Would you like to let this website use speech to text?” “Always remember my choice for this domain”. Seems giving the user a master switch that overrides things, and letting websites detect this and complain, doesnmr have many downsides but has tons of upsides. And then of course there is browser fingerprinting. It’s now really hard to turn it off without breaking tons of sites that care about the width of your window (size of your phone) and your operating system, and so on
  - sangnoir 7y ago
    LED brightness is controlled by pulse-width modulation: at low frequencies, the camera LED would appear dimly lit. A more sophisticated approach might be to combine gaze detection to ramp-down frequency if someone is looking towards the camera/LED.
    - 7y ago
outworlder 7y ago
> From my understanding, Apple has done sort of what you're asking for, they've hooked up the physical wiring of the camera LED to the camera itself, so it is physically impossible to power the camera without the LED being turned on Correct. And that was my reason for NOT covering the camera. Because I would be able to see if it was on due to some malware. However, I did not expect a vulnerability like Zoom's, where a simple website would be able to trigger a webcam. Combined with external monitors, the LED would be potentially missed for a good amount of time. So I've reversed my position since then.

by atonse 7y ago

jonny_eh 7y ago

What about the mic?

t34543 7y ago

I’ve read this as well but my macbook senses ambient light and adjusts my backlight accordingly. Isn’t this through the camera - with no LED?

Analemma_ 7y ago
No, the ambient light sensing is done with a light sensor on the body - look for the tiny hole drilled into the chassis. It doesn't use the camera.
- ljm 7y ago
  Remember when they did that for your battery power indicator! With a little button to trigger it.
eightysixfour 7y ago
https://apple.stackexchange.com/questions/347895/where-is-the-true-tone-ambient-light-sensor-on-the-2018-macbook-pro https://apple.stackexchange.com/questions/347895/where-is-th...
klodolph 7y ago
The ambient light sensor is right next to the camera, I think it's usually to the left. It's a bit hard to test since they're close together. Macs have had ambient light sensors for a long time. For example, take an old iMac and put it to sleep. The power light will pulse with a period of about 2s, and the brightness will depend on the ambient light level. Edit: Just tested on my MBP. Opened photo booth, covered the camera with my thumb, shone a bright flashlight at the point just left of the camera. The display got brighter but Photo Booth showed no changes in what the camera was seeing.

skybrian 7y ago

That's useful, but it's not as reassuring as a hardware switch where you can see it work. (For video, anyway. I don't see any similar solution for audio.)

ehsankia 7y ago
Two reasons why switch is better: 1. If it does happen to light up, what would you do, turn off your computer? That's shitty. 2. What if your AFK and aren't looking at the light?
- toxik 7y ago
  Arguably better to be aware of the breach than prevent one sensor from leaking too.
- ljm 7y ago
  A switch plus a notification (as opposed to modal prompt) if you try to get into video/audio calls but forget to flip it back. Just to remind you that you’re trying to enable video/mic but have the hardware switched off.

XCSme 7y ago

I remember there was a story saying that it's possible, via software only (due to a "bug" and some "poor" hardware design), to turn on the camera without activating the LED.

Nextgrid 7y ago
It used to be that the LED was controlled by firmware. As far as I know this is fixed now but I haven't proven it myself. There are leaked schematics of MacBooks online (that unofficial repair shops use) so if you want to investigate this I'd expect it to be a good place to start.
css 7y ago
https://jscholarship.library.jhu.edu/handle/1774.2/36569 https://jscholarship.library.jhu.edu/handle/1774.2/36569 (2013)
- seandougall 7y ago
  Published in 2013, but describes "the Apple internal iSight webcam found in previous generation Apple products including the iMac G5 and early Intel-based iMacs, MacBooks, and MacBook Pros until roughly 2008".

SlowRobotAhead 7y ago

FWIW... I bet you could power the camera, get a still frame at 60fps, shut it down, and not see the led come on. It would be 1/60, 16ms plus or minus the amount of overhead needed, plus autofocus and exposure correction might make it impractical, but it’s definitely not a bulletproof fix.

heavenlyblue 7y ago
Apple could simply make the camera take 1 second to activate.
- SlowRobotAhead 7y ago
  Slow spool up embedded devices... we’re moving backwards :)
  - heavenlyblue 7y ago
    If Google Calendar thinks it’s OK to set a 500ms animation on opacity for event edit dialog - then it doesn’t seem like a 1 sec spooling for a webcam is too much :)
cstejerean 7y ago
How much would you bet?
- SlowRobotAhead 7y ago
  Considering I have a device here that has an I2C camera and in firmware I can turn it on and off at right around 25ms, I’d consider betting quite a bit. Instead of being snarky, how about you explain why this isn’t possible. Even if it was 100ms almost no one would catch that.
  - cstejerean 7y ago
    I’m not being snarky, and we’re not talking about some random device you have. We’re talking about the camera on a Mac. The bet is that you can’t turn it on and off so fast as to be un-noticeable because there is a noticeable delay between that light turning on and getting an image from that camera. So I’ll gladly take the other side of that bet.

Wowfunhappy 7y ago

This is a better solution overall, as it's "by default". A hardware switch relies on the user to be privacy conscious. An LED which is physically connected to the camera circuit (!) is immediately noticeable if it turns on unexpectedly.

rxhernandez 7y ago
As a layperson in this arena, I'm skeptical as to whether it's a great solution. Is it possible to turn the camera on and off very quickly? If so, a smart hacker could do that really quickly and if the owner ever notices they would probably think there is a problem with the electrical rather than thinking they are being monitored.
- EGreg 7y ago
  It is just like the small hacks that are possible with ANY of these “require UNRELATED user interaction” things. Like being able to speak “” when the user clicks. Or something really short or kind of unpronounceable like “,,,,”. Apple could of course try to require the first speech to always be long enough to be unmistakably speech. But otherwise ANY user interaction is enough to enable ANY speech. The alternative would he to have dialogs for everything: “would you like to turn on the camera?” “Would you like to let this website use speech to text?” “Always remember my choice for this domain”. Seems giving the user a master switch that overrides things, and letting websites detect this and complain, doesnmr have many downsides but has tons of upsides. And then of course there is browser fingerprinting. It’s now really hard to turn it off without breaking tons of sites that care about the width of your window (size of your phone) and your operating system, and so on
- sangnoir 7y ago
  LED brightness is controlled by pulse-width modulation: at low frequencies, the camera LED would appear dimly lit. A more sophisticated approach might be to combine gaze detection to ramp-down frequency if someone is looking towards the camera/LED.
  - 7y ago

outworlder 7y ago

> From my understanding, Apple has done sort of what you're asking for, they've hooked up the physical wiring of the camera LED to the camera itself, so it is physically impossible to power the camera without the LED being turned on Correct. And that was my reason for NOT covering the camera. Because I would be able to see if it was on due to some malware. However, I did not expect a vulnerability like Zoom's, where a simple website would be able to trigger a webcam. Combined with external monitors, the LED would be potentially missed for a good amount of time. So I've reversed my position since then.