Lockdown Mode on the Librem 5: Over and above Hardware Destroy Switches, Next TGP

Kyle Rankin

Main Stability Officer
PGP ID: 0xB9EF770D6EFE360F
Fingerprint: 0DFE 2A03 7FEF B6BF C56F73C5 B9EF 770D 6EFE 360F

Lockdown Mode on the Librem 5: Over and above Hardware Destroy Switches, Next TGP

Hottest posts by Kyle Rankin (see all)

When I convey to people I do the job for Purism and I’m asked what Purism does, the explanation I give to the regular individual is along the lines of: “we make privacy and safety respecting components that runs free of charge software package.” Straight away following that, I just about generally issue to our hardware destroy switches to demonstrate how we acquire a distinctive strategy from most other components out there. To me it’s a great instance of a uncomplicated, uncomplicated-to-have an understanding of protection measure that provides a tangible profit to absolutely everyone.

Lockdown Mode on the Librem 5: Over and above Hardware Destroy Switches, Next TGP

Like with our Librem laptops, our Librem 5 smartphone will also function get rid of switches but not like the laptops it will have a few eliminate switches, not just two:

  1. cameras and microphone
  2. WiFi and Bluetooth
  3. mobile baseband

Afterwards in this submit I’m going to explain an fascinating new aspect for our Librem 5 cell phone we are contacting “Lockdown Mode” that extends our normal get rid of switches to present even a lot more security and privacy but initially I will make clear the existing use, and explanations driving, every single kill switch – as well as talk about some of the privacy and security threats with other sensors on the telephone that have led us to put into practice Lockdown Method.

Cameras and Microphone Eliminate Swap

The cameras and microphone destroy swap is arguably even much more significant on a phone than on a laptop computer. When the webcam / microphone kill switch on our laptop computer can aid guard you from malware that may snoop on you through the webcam without having your knowing, at the very least it could only snoop on you whilst you are all over your laptop. Most folks have a tendency to have their phones with them everywhere so the privateness dangers are considerably increased if your microphone and cameras are normally on.

WiFi and Bluetooth Eliminate Change

Like with the digital camera and microphone, the WiFi and Bluetooth destroy swap has even higher importance on a mobile phone than on a laptop. Disabling WiFi and Bluetooth can shield you from external above-the-air attacks if you are in a higher-chance location (or a vulnerability will come out for your WiFi or Bluetooth card). Protecting versus remote assaults is not the only gain of this kill change while, disabling WiFi in unique can also safeguard you from monitoring.

Given that your cell phone is in your pocket, your WiFi hardware detects compatible networks nearby as you transfer all-around. Even if you do not affiliate with the networks all over you, the mere actuality that your components can see them allows the cell phone (and apps on it) to know you are in the vicinity of those people devices. As you go, your distance to all those equipment improvements, which variations the toughness of the signal and aids triangulate exactly where you are for any firm like Google that has a database of WiFi entry points, together with their locale. By eliminating electricity from your WiFi hardware, you can be certain that any applications that may well try to observe your location with WiFi are blocked.

Cellular Baseband Kill Switch

The mobile baseband get rid of swap is special to the Librem 5 and completely removes energy from the mobile modem in the Librem 5. Even if you aren’t involved by the risks because of to the simple fact that mobile modems run thriller code and have accessibility to all communications that go in excess of them, you nevertheless ought to be knowledgeable of, and involved by, the tracking and privateness concerns. To route calls and facts to your mobile phone, your cellular service provider demands to triangulate your posture with respect to the towers in your place. As a outcome, as extended as your cellular modem is on, your company understands where by you are. Your phone’s OS also uses this tracking knowledge to supplement (or in position of) GPS so apps on your cellphone can also know wherever you are.

Putting a destroy swap in the Librem 5 intended a style and design not like many of the present telephones out there that blend the CPU and mobile modem into a one chip. We deliberately break up out the baseband onto a replaceable M.2 card. This not only allows you physically get rid of the baseband altogether, but allows you electrical power it off with a kill switch. If you want to know for certain that your cellphone is not monitoring you, you can flip the change and know for specified that it’s off.

One major challenge when safeguarding your privacy on a cellular phone is that, in contrast to an common laptop, a cell phone is complete of a lot more sensors and other hardware that could be employed for monitoring and spying. A large amount of protection study around the past decade has shown just how considerably info can be derived by seemingly harmless sensors that are included on a cell phone.


GNSS, which supports GPS, GLONASS, Galileo and Beidou – as perfectly as SBAS augmentation services like WAAS, EGNOS, GAGAN and MSAS – is useful for navigation computer software, as it supplies your exact coordinates where ever you are on Earth. Despite what some folks could feel, the GNSS is a passive machine. By itself, it can’t transmit your place to any individual, it can only choose up alerts from GNSS satellites and use them to compute your present-day situation. That reported, if your GNSS is on, even if your network is disabled, any software package on your process with entry to the GNSS can log your place, and transmit that log later.


The IMU chip supplies a cellphone with a compass and accelerometer it can use along with a GNSS to convey to what way you are heading. An accelerometer is also a valuable sensor to deliver more phone options these kinds of as detecting the orientation of the cellular phone so that it can rotate the screen, deliver metadata to the camera, and even detect when you decide on it up, set it in your pocket, or flip it more than and put it back again on the evening stand.

There are some privateness and protection hazards with the accelerometer, however. Safety researchers in excess of the a long time have found methods to detect what you are typing on the screen merely by seeking at variations in the accelerometer. Also, becoming ready to log the speed and course of your phone, mixed with detecting nearby WiFi access details could (in concept) present a pretty accurate monitoring device even with GNSS disabled.

Ambient Light and Proximity Sensors

The ambient gentle and proximity sensors on a cell phone provide a selection of helpful functions we use just about every working day. Among them the light-weight sensor aids the mobile phone modify the backlight brightness based mostly on the obtainable ambient light-weight, which can aid with electric power price savings. The proximity sensor assists detect when you spot the cell phone up to your face, so it can lock the screen and prevent you from accidentally triggering touchscreen button presses with your deal with. These sensors feel rather harmless, but protection researchers have demonstrated how the light-weight sensor can be utilized to fingerprint a individual person and even to map out the arrangement and size of their house.

So we have 3 kill switches, nevertheless there are so several other sensors that we may possibly want to transform off. It’s correct that folks could disable hardware inside the OS and considering that PureOS is absolutely free software and Purism is an ethical business, you have additional rationale to have faith in that disabling the components with application essentially operates. That claimed, the full concept of the hardware kill switch is to deliver you that more assurance that a piece of hardware is genuinely off.

Whilst we could include eliminate switches for each personal piece of components, getting 3 get rid of switches currently pushes the limits with respect to room on the mobile phone, the complexity of the hardware and the all round person practical experience. So if you set the higher restrict on kill switches to three, there are a amount of unique means you can deal with the trouble with these excess sensors which includes:

  • Only disable all those sensors with software program
  • Group sensors with a single or extra current destroy switches
  • Lockdown Manner

We have assumed via all of these unique solutions, between many others, and we made the decision that it was far better to provide the alternative for additional stability to these who seriously want it. We have chosen a answer we are contacting Lockdown Manner, that gives men and women who want this excess level of security the selection to switch all sensors off quickly, with no imposing extra complexity on an regular person.

How Lockdown Method Works

To set off Lockdown Manner, just change all three eliminate switches off. When in Lockdown Mode, in addition to powering off the cameras, microphone, WiFi, Bluetooth and cellular baseband we also cut ability to GNSS, IMU, and ambient gentle and proximity sensors. Lockdown Method leaves you with a correctly usable transportable pc, just with all monitoring sensors and other hardware disabled. If you switch any of the components eliminate switches again on, the components that corresponds to that switch powers on along with GNSS, IMU, and ambient mild and proximity sensors.

What About Offline Navigation?

A person of the most clear facet outcomes of Lockdown Method is the capability to use the GNSS with purely offline maps. Take note that you even now can do this on the Librem 5 in a number of distinct strategies, by flipping any a single of the get rid of switches back on and then disabling the corresponding components in software. For occasion, if your largest problem was transmitting your location, you could go away the WiFi / Bluetooth and mobile baseband off, transform on the cameras and microphone and disable those in software program as an alternative. Those people who have to have a offline navigation but have this sort of a large amount of threat that they just cannot accept the hazard of disabling the cameras and microphone in software, could physically get rid of the cellular baseband hardware from the cellular phone and go away that get rid of change on.

There is a ton of opportunity to extend Lockdown Manner previous just disabling hardware into software program, and we are checking out some of those people choices now. For instance, the OS could detect when Lockdown Mode is enabled and instantly lock your screen. Those people who are beneath even better threats could perhaps have Lockdown Method empower additional defenses inside of the OS, disable sure products and services, or even shut down or wipe the mobile phone (whilst I’d propose you set up some variety of PIN prompt for that previous a person, in case you result in all the switches by incident). There are a whole lot of possibilities for this new aspect and I’m on the lookout forward to seeing how our buyers prolong it on their very own phones.

About Purism

Purism gives large-good quality privacy, protection, and freedom-concentrated pcs, telephones, and application. Our system is meant to empower anyone, which include privateness-aware people, business people, enterprise folks, builders, writers, electronic artists, activists, geeks and defenders of freedom all all-around the environment.

Kyle Rankin