151–160 of 249 posts
I think we should appreciate that while this isn't the best or most secure design (I'm not that happy with the host controlling the reset), it at least has an LED that shows the microphone status, which can't be controlled by software.
I think this is the very bare minimum we should require from all our digital devices.
Conclusion: > But, basically if one presses the switch it causes the flip-flops to change state and to then either add or remove power from the microphones. > The 'mute' button appears to be very real and functional. When the button glows 'red' the power is removed from the microphones.
> The SOC (system on chip) controller seems to be connected to the flip flop resets, which makes sense as the product powers on with the microphone enabled as default.... It sounds like you could press mute, walk away and it could reset unmuting itself in the process without you realizing. You would need to constantly monitor that LED for assurance it is still muted. It’s not clear to me from the article how the SOC…
An OTA firmware update can change this behavior overnight. Unless it's a physical bounce switch that actually disconnects power mechanically, you are still at the mercy of someone else.
Incorrect. The main conclusion of the article is that firmware can't affect the function of the switch.
The fact that the mike defaults to on after power on is completely understandable from a user interface perspective, but from a security perspective it makes the mute switch useless. Why? Because any attacker that has penetrated far enough to be able to control the SOC in order to snoop can also trigger a SOC reset in order to make sure that the mike is enabled before they start snooping. A physical switch would have…
At least it sounds like the red light would go out in this case, so you'd have some indication that something is up.
Nice to see electronupdate here. For those who don’t know, he also has a YouTube channel[0] where he does teardowns of random ICs. It’s quite interesting seeing the die shots. I’m assuming this post is a continuation of his “part 1” post/video from a week and a half ago[1] about the Echo Flex. His videos are definitely not scripted (and barely edited), which can be off putting to some (hearing “umm”s among other thin…
You'd think that he'd be better at interpreting IC markings by now, though.... Part 1 is not "ICFJ", it's "CFJ". The line is the pin 1 marking. This one is the harder of the two; however, if you've been doing this a while, you'd recognize this SOT23-5 as coming from TI, whose online marking code lookup returns "SN74LVC1G14DCK" in just a few seconds. (Incidentally, that means the actual marking is "CF" with a lot/date…
If the transistor is a PMOS like the author says, when the output of the NAND goes low wouldn't both the LED and the transistor turn on?
The way the LED is drawn it should turn on when the NAND output is sinking current, right? Maybe the LED is drawn upside down? Or am I misreading/misunderstanding something really simple?
Earlier quoted context omitted.
I think accidental unmuting due to random events would translate into “theyare listening to me” in their average customer’s mind, and would be a pr disaster. Compare the cost of that to an extra component, and the surprise goes away.
There’s no “extra component” in the physical design. Both flip-flops are in the single 74x74 package and if you’re only using one, you have to drive the other to a known state anyway, so why not use them both anyway?
Earlier quoted context omitted.
Also a minor hardware re-design may change mic switch behaviour in the future without that change being noticeable to the buyer. You'd really need regular tear-downs of a sufficient sample-size of devices to make sure that you can actually trust newly bought devices with sufficiently high confidence.
It depends how paranoid you are. If you believe your audio is so valuable that Amazon would create a separate hardware model for you and those like you, and would succeed in keeping that a secret, then yeah you still shouldn't buy an Echo. You will also not want any other always-on devices with microphones and network connections, like a phone or laptop. 99.9% people are not in this category.
Did you really have to acid etch a chip package to find this out? Can’t you measure current/voltage across the microphone?
Measuring the current of the microphone would only tell us that at a specific moment, the microphone is off and the LED is red. But that might be a software switch, in which case nothing would prevent Amazon to turn the microphone from time to time while keeping the LED red.
Earlier quoted context omitted.
How is it different from having a mobile phone on the table?
I think the issue is one of the consumer's intent: are you buying a phone with a bunch of extra capabilities or a microphone hooked to a data center around the world? And that explicit decision is what is jarring to people who value privacy. Of course they both have microphones hooked to data centers, but the Alexas/Echos are almost worthless without the microphone enabled. Many people I know have turned off listenin…
Yes.