After using the Librem 5 for a while, the number one imperfection with it is the lack of a kill power switch and/or a kill GPS switch. One of the best aspects of the phone is that hardware switches make it impossible for malware to track you when you are not using the phone. However, the phone itself is always powered, and only software blocks the GPS. What prevents malware from tracking your movements, saving that info while the phone is ‘off’, and then sending it to a bad actor when you go to use the phone? It seems that only software prevents this. Have I missed something?
Also, most of the time my phone is ‘off’. Even if a kill power switch only increases battery life by 10%, that is a very needed improvement. I would even be willing to buy a new Librem 6 phone if it did that!
Thanks for the quick response, and for the info. However, I am still unclear about what is hardware, what is software, and what is firmware. Is ‘lockdown mode’ software, hardware, or firmware? If firmware, while that is software with one additional security layer, it ultimately is ultimately just better protected software. Is it not?
To trigger Lockdown Mode, just switch all three kill switches off. When in Lockdown Mode, in addition to powering off the cameras, microphone, WiFi, Bluetooth and cellular baseband we also cut power to GNSS, IMU, and ambient light and proximity sensors. Lockdown Mode leaves you with a perfectly usable portable computer, just with all tracking sensors and other hardware disabled. If you switch any of the hardware kill switches back on, the hardware that corresponds to that switch powers on along with GNSS, IMU, and ambient light and proximity sensors.
→ it’s hardware based. If you want to explore more, you can take a look at the schematics (links should be in wiki/FAQ). There are also some old threads from years ago, if you search the forum.
Search for 3SW_KILL … as an output on page 10 and as an input (to the GNSS chip) on page 14.
The GNSS chip will not have power - period - if all three kill switches are in the “power off” position.
Note that lockdown mode also affects the sensors. If you were facing a sophisticated adversary’s malware, the accelerometer could be used for dead reckoning, I guess, to establish your location. So the entire sensor package is killed (powered off) in lockdown mode.
While kill switches are great, your first line of defence against malware should always be to prevent it existing on your computer in the first place - by not intentionally / voluntarily installing malware and by keeping your software up to date. I imagine that that is not news to you.
Tracy: I wish what you said was always true, but not always. It is very common for modern devices to only monitor a switch, like it was just another sensor, and then modify its behavior based on what it read. This makes devices cheaper to manufacture, but also a little easier to hack. Purism has shared the schematic diagram for the phone, and I will give it a look soon. Thank you for the comment though. Discussion like this is how we all learn!
You can’t remotely modify a hardware switch.†
There seems to be a misunderstanding here. Some respondees don’t seem to understand what the term “hardware” means (like wierdnerd says above). There are three switches on the side of the L5. You need to physically move them with your fingers (or maybe a fine point, like a bent paperclip, a pen, or needle). They form a break in the circuit.
† Unless some AI sends a robotic cockroach to move the swtiches when you’re not looking.
I don’t know but I think that button is more complex. I don’t think you can override or prevent the hard poweroff from the power button in the operating system. So, again, I would suggest that “off” means “off”. The complication comes because a short press and release of the power button has a different effect as compared with press-and-hold.
Then there’s removing the battery, if you really really want to poweroff completely, again in the absence of a robotic rodent.
