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Amazon Echo Flex: Microphone mute button appears to be real and functional

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Re: Amazon Echo Flex: Microphone mute button appears to be real and functional

#112

Earlier quoted context omitted.

In order to use a physical debounce switch, there are several steep challenges. You can imagine OP presenting to an audience of 14 people at Amazon Devices group with a slide titled "New BOM proposal" entailing 6 million devices x [$0.0273 (switch price at 100k qty) + $0.05 assembly cost] + $50k engineering NRE (650 engineering hours) + $35k tooling NRE + $22k FCC re-cert + 7k ESD cert + another $100k in various cert…

You'd make this change alongside others that would require recertification and retooling anyway, and presumably a lot of those engineers have a full-time contract so that's not an additional cost. Overall assembly cost may be higher or lower depending on those other changes. It really is just that $0.0273 for the switch, which compared to the very steep marketing and branding challenge of convincing privacy-minded fo…

Engineers, with contracts or not, have about 2200-2500 hours to spend per year. Those hours can presumably be allocated to this task (that doesn't add any new capability) or to a task that adds capabilities (which will bring in new revenue).

Re: Amazon Echo Flex: Microphone mute button appears to be real and functional

#113

Yes that is the technical conclusion. But maybe the most important thing is that we have to do an actual teardown of the product in order to have some confidence that Amazon is not lying on it's Echo capabilities. To be clear, I am not saying we should trust Amazon & Co, I'm saying that if that's the level of trust we have with home assistance devices, why even bother with the stuff ?

We have options of either to trust the company or some other auditor. We can try getting some laws made to ensure honesty, but I personally don't like that route this early in the technology. What we need a completely independent organisation like EFF to audit and certify basic guarantees around privacy/safety. The companies should also prefer this route as it would give take some heat off in EU/Congress without crea…

> We can try getting some laws made to ensure honesty

I'm pretty sure we already have laws to ensure honest advertising. The problem is that it's hard to tell the difference between malice and incompetence.

Re: Amazon Echo Flex: Microphone mute button appears to be real and functional

#114
post #85

Earlier quoted context omitted.

Then OP sees newsflash on TechCrunch "Amazon Echo Flex v2 is failing in low humidity conditions". Goddamn it, Andrew (at the reliability lab). OP goes home and opens a bottle of Amazon basics wine.

This comment along with your previous one give the impression that in effect any solution that is favorable for the user is not only going to "cost too much to do just for the customers" but is also bound to be less reliable. It's how every privacy invasion or abuse of position of the past decade+ has been justified: "we made the product cheaper and better for you, any change will cost a lot and break it". Because ye…

Sometimes it gets absurd. You can hardly buy any modern laptop with a hardware camera switch. It's as if laptop manufacturers were completely blind what number of people uses a hardware solution in order to render their laptop cameras unusable when they want it. The same group of people would love to be able to do the same with their built-in mics (not just in laptops, but also phones). We're not talking about clueless folks but all kinds of people, including tech-aware ones like Zuckerberg. Nevertheless, mobile device manufacturers remain deaf and pretend the problem doesn't exist. And Librem is the exception that proves the rule.

Re: Amazon Echo Flex: Microphone mute button appears to be real and functional

#115

Earlier quoted context omitted.

You'd make this change alongside others that would require recertification and retooling anyway, and presumably a lot of those engineers have a full-time contract so that's not an additional cost. Overall assembly cost may be higher or lower depending on those other changes. It really is just that $0.0273 for the switch, which compared to the very steep marketing and branding challenge of convincing privacy-minded fo…

I agree with you on excluding certification costs if you’re going to respin the device anyway, but part, assembly, and NRE labor are real costs of this change.

Which should remind companies releasing similar products in the future that it's cheaper to design them with built-in privacy features rather than patch them as an afterthought.

Re: Amazon Echo Flex: Microphone mute button appears to be real and functional

#116
To wear a tinfoil hat for a moment:

> The SOC (system on chip) controller seems to be connected to the flip flop resets

> The 'mute' button appears to be very real and functional. When the button glows 'red' the power is removed from the microphones.

Does the microphone take any time to boot up? How far could a malicious SoC get by toggling "reset" on and off very fast? If you toggle the microphone on and off at 96kHz with e.g. a 1% duty cycle, then you'd be able to sample the level from the microphone at 96kHz, and the LED would still be glowing at 99% of its usual current (which would be visually indistinguishable from 100%). This would allow the SoC to record audio at full quality, and still leave the LED glowing.

Re: Amazon Echo Flex: Microphone mute button appears to be real and functional

#117

Red light used to indicate recording, traditionally. I'd expect the light to be green when I'm safe from spying.

Not sure why this was voted down, as that's the way I'd expect it to work as well. The red light should flash or pulsate when recording, in fact. Otherwise, people without good color vision might miss the cue.

While a multi-color LED would be preferable, if only a single LED could be spared then it's better that it's on to indicate mic is off.

Otherwise the LED could fail and you wouldn't be able to tell if the mic was on.

As is, you assume the mic is on if the LED fails, which is preferable from a privacy point of view.

Re: Amazon Echo Flex: Microphone mute button appears to be real and functional

#118
post #69

Earlier quoted context omitted.

Then don't buy one.

With Alexa and it's ilk being integrated in ever more home electronic devices, not buying one is becoming increasingly impossible.

Put them on their own network, make sure that network is not routed/connected with the internet.

Or, if possible, dont connect to a network at all.

Re: Amazon Echo Flex: Microphone mute button appears to be real and functional

#119

To wear a tinfoil hat for a moment: > The SOC (system on chip) controller seems to be connected to the flip flop resets > The 'mute' button appears to be very real and functional. When the button glows 'red' the power is removed from the microphones. Does the microphone take any time to boot up? How far could a malicious SoC get by toggling "reset" on and off very fast? If you toggle the microphone on and off at 96kH…

So I picked the very first mems microphone datasheet my ddg gave me: https://www.st.com/resource/en/datasheet/mp34dt06j.pdf

..and it says 10 ms max turn on time, so 100 Hz.

Of course, a typical or minimum turn on time could be better, but I imagine it it were better, it would be advertised as well.

Re: Amazon Echo Flex: Microphone mute button appears to be real and functional

#120
post #15

Disclosure: I'm an Amazon Devices PE, but not on Alexa devices. Jeff (and others) have spoken publicly about this in the past, and this teardown is correct. The hardware is designed such that, if the privacy LED is on, the microphone is unpowered. In order to compromise that, one would need to physically alter/damage the hardware.

Your statement really isn't any different than saying "Amazon says the mute button is real". Which we already knew. The problem is that many people don't trust the good faith of the company you work for, and by extension they won't trust you either.

If you don't trust the mute button, don't buy an Echo.
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