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Comment by justin | Hacker News Reader

I would be more concerned about the microphone. I can easily cover the camera with tape. Also, random pictures of me programming or reading HN are probably less damaging audio recordings of conversations I might be having.

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My current Thinkpad has a physical switch to disable radios. I'd like to have a physical 'privacy' switch that cut the power to internal microphones and cameras. To be security aware, this has to be an auditable hardware power switch, and not just an interrupt/driver/bios combination that could be bypassed. It's also prefereable for security to have a an off-by-default switch, than an activity light you might not notice...

Great idea. Must be a physical switch that just cuts all physical links between the camera/microphone and the rest of the system, so that no reprogramming is possible. Unfortunately, little chance to see it in Apple products, as such switch would probably not look "slick" and would probably be considered "confusing for the user" and as such not suitable for implementing.

> Unfortunately, little chance to see it in Apple products, as such switch would probably not look "slick" and would probably be considered "confusing for the user" and as such not suitable for implementing.

That was my first thought, but then I realized the absolutely ridiculous extent to which Apple goes to build secure devices, and how "slick" the mute switch is on iPhones and iPads.

I wouldn't bet against it.

That's unfortunately the exception rather than the norm. I have seen laptops with switches for WiFi, and camera obturators, but manufacturers hardly think about these things. It's obviously not an Apple problem only, but it certainly hinders usability to have physical switches. Yet, I really wished they'd make that standard for all media peripheral (and not just on PC, but any device coming with these features). That would however be easily considered as an admission of failure to provide a secure software environment to their customers, and they might not like that aspect of it.

It's also cheaper to "just do it in software". Some laptops will seriously overheat if left turned on without an OS loaded, because the *s that designed them didn't even bother to hook up the temperature sensor to the fan controller and left the "hook up" to OS-level drivers.

My current ThinkPad (T400) has the Mic, fingerprint scanner and webcam disabled physically. They're easy to get into and unplug.

Agree entirely though.

I'd rather like a physical off switch as well like the original IBM PC (the big red lever)

My ThinkPad for the paranoid (X201i) has none of those devices at all...

My Dell has a wireless switch also, but it doesn't work under Linux, only Windows. In Linux, the radio remains on no matter what the position of the switch is. Meaning its's really a software switch, and hence worthless for security.

Sorry to burst your bubble but actually that "physical switch to disable radios" is, if I remember correctly, just another signal to the wireless card (which runs its own firmware as well). It's not a true power kill.

Same here. Even nude photos would be embarrassing, but audio recordings could have effects far worse than some prude shame.

Especially since there is no LED to signal the microphone is active, it doesn't need to point anywhere. If it could be activated while the laptop is closed (force wake up a part of the OS for just a few minutes here and there for instance) it would be a really tough problem.

Maybe unload/delete the kernel module? (This is how I used to silence the pcspkr beep on Linux.)

But how do we do that on the more and more locked-down computing appliances consumers gravitate towards?

One does not simply unload/delete kernel module on an iPad...

Recent versions of iOS ask for permission to use the microphone.

What if in the case of a "lawful intercept" iOS does not ask for permission?

The beauty of your comment is that just a little over half a year ago you'd be considered a complete conspiracy nut and a paranoid tinfoil hatter but today there's no one even saying anything against you.

No, an attacker can just reload it. The hardware is still there, waiting for a driver to control it.

I use a cut-out piece of postit note for the camera, and a small piece of etape for the microphones -- seems stable, and both are pretty easy to take off without leaving too much spooge behind.

Does tape actually provide enough impedance to prevent surveillance through your microphones? Seems like all an attacker would have to do is amplify (and possibly filter) the audio a bit.

I turned up the mic all the way, did a skype test call. I could hear myself if I shouted (input level=0). If I talked at a normal volume level, it was audible (and the input level showed as 2/15. I might try a couple of layers of tape...

EDIT: Yeah, 2nd layer of tape = 0 input level even if I shout really, really loudly. You can't imagine how much my coworkers are enjoying this experimentation!

I wondered about tape along with a suitable sound-dampening material, so this "seat-of-the-pants" experiment is of interest to me.

I'd want something more certain for a higher security situation, but this might do me for some "casual" use cases.

Skype has a noise gate - any play on the microphone below a certain level is cut off. Someone with direct access to your microphone can listen without the noise gate and might still hear.

What about internal microphones on MB's?

osascript -e 'set volume input volume 0' doesn't really produce the expected result…

plug a square card reader in the jack.

Doesn't physically turn off the internal microphone. I've found out the hard way: I have a headset with a hardware mic switch. If this switch is in the "off" position when headphones are put into the jack, the mic built into my mac still operates.

This is with a mid-2012 macbook model.

Plus on MacBooks there is a second microphone to gather surrounding noise to improve sound quality. I don't think there is any non intrusive way to stop it from activating either.

That's because the switch probably makes it look to the mac as if there's no microphone at all.

You can, for example, set up an aggregate audio device in the audio input/output config panel to enable all inputs and outputs to work at the same time. So it's not unreasonable to think that the internal mic could be activated even with something plugged into the jack.

Well I was playing around a bit more, and I was able to disable the(or a, not sure how many are in 2010 MBPs) internal mic by taking an old audio input jack (cutting the wires), plugging it in (so it looks like a nub sticking out), going to the audio settings and setting the audio port from "Sound Output" to "Sound Input" and the internal mic picked up no readings. Still trying to figure out how to do that from the command line.

I put a piece of paper over the camera, then tape over that. That doesn't leave glue on the lens.

Also note that a speaker can be used as microphones as well. (In physics terms they are the same device, which can convert sound to electricity or vice versa.) With modern sound cards having reprogrammable inputs and outputs, I wouldn't be surprised if even a laptop with no microphone installed could record audio.

(My friend once had to record herself for a foreign language homework, but her microphone broke. I instructed her to plug her headphones into the microphone jack and ust them instead. It worked, but she had to talk loudly to make them work.)

Not to mention microphone can work as a key logger http://rakesh.agrawal-family.com/papers/ssp04kba.pdf

The RSA acoustic key recovery hack is particularly terrifying in this instance. Turning on the microphone on the computer can furnish an attacker with everything they need to recover encryption keys stored on the computer.

Some hardening guides suggest having the camera and microphone removed by an apple tech. I'm considering having this done on my next laptop - I just don't use them that often.

That's one big advantage of my old FireWire iSight camera – if the FireWire cable isn't plugged in, you _know_ it's not taking pictures.

(And now I half expect to read a new Snowden paper tomorrow detailing how the NSA coerced Apple into fitting batteries and flash storage into webcams so they could be instructed to covertly record video while not plugged in and upload it automatically later…)

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